Add detailed implementation plan and tests for 2026 security audit fixes

Co-authored-by: Copilot <copilot@github.com>

.claude/settings.local.json

@@ -33,7 +33,17 @@
       "Bash(git -C \"c:/Users/laure/Documents/Gitea/brainwave\" diff .gitea/workflows/deploy.yml)",
       "Bash(git -C \"c:/Users/laure/Documents/Gitea/brainwave\" diff HEAD -- .gitea/workflows/deploy.yml)",
       "Bash(git -C \"c:/Users/laure/Documents/Gitea/brainwave\" log --oneline -3 -- .gitea/workflows/deploy.yml)",
-      "Bash(git -C \"c:/Users/laure/Documents/Gitea/brainwave\" log --oneline origin/main..HEAD)"
+      "Bash(git -C \"c:/Users/laure/Documents/Gitea/brainwave\" log --oneline origin/main..HEAD)",
+      "Bash(grep -E \"\\\\.tsx$\")",
+      "Bash(Get-ChildItem -Path \"c:\\\\Users\\\\Laurens Bartelds\\\\Documents\\\\Gitea\\\\brainwave\" -Force)",
+      "Bash(Select-Object Name)",
+      "Bash(git -C \"c:/Users/Laurens Bartelds/Documents/Gitea/brainwave\" stash list)",
+      "Bash(git -C \"c:/Users/Laurens Bartelds/Documents/Gitea/brainwave\" stash pop)",
+      "Bash(git -C \"c:/Users/Laurens Bartelds/Documents/Gitea/brainwave\" diff --stat HEAD)",
+      "Bash(git -C \"c:/Users/Laurens Bartelds/Documents/Gitea/brainwave\" checkout -- .claude/settings.local.json)",
+      "Bash(git -C \"c:/Users/Laurens Bartelds/Documents/Gitea/brainwave\" diff HEAD -- frontend/src/components/Overview.tsx)",
+      "Bash(npm test *)",
+      "Bash(git -C \"c:/Users/Laurens Bartelds/Documents/Gitea/brainwave\" diff HEAD -- backend/src/validators/adminSchemas.ts backend/src/validators/adminSchemas.test.ts)"
     ]
   }
 }

.gitea/workflows/deploy.yml

@@ -1,4 +1,4 @@
-name: Deploy ARM to OrangePi
+name: Deploy ARM to OrangePi
 
 on:
   workflow_run:
@@ -26,11 +26,23 @@ jobs:
           echo "SSH_AUTH_SOCK=$SSH_AUTH_SOCK" >> "$GITHUB_ENV"
           echo "SSH_AGENT_PID=$SSH_AGENT_PID" >> "$GITHUB_ENV"
 
-      - name: Write Inventory
-        # StrictHostKeyChecking=no is intentional for a known home-network host.
-        # To harden, add the host fingerprint as a secret and use a known_hosts file.
+      - name: Pin server host key to known_hosts
+        env:
+          HOST_KEY: ${{ vars.SSH_HOST_PUBLIC_KEY }}
         run: |
-          printf '[orangepi]\norangepi ansible_host=%s ansible_user=%s ansible_ssh_common_args="-o StrictHostKeyChecking=no -o ForwardAgent=yes"\n' \
+          mkdir -p ~/.ssh
+          chmod 700 ~/.ssh
+          if [ -z "$HOST_KEY" ]; then
+            echo "::error::Repository variable SSH_HOST_PUBLIC_KEY is not set."
+            echo "::error::Pin the server's host key instead of trusting ssh-keyscan over the network:"
+            echo "::error::run 'ssh-keyscan -t ed25519 <host>' once from a trusted network and store the full output line in SSH_HOST_PUBLIC_KEY."
+            exit 1
+          fi
+          printf '%s\n' "$HOST_KEY" >> ~/.ssh/known_hosts
+
+      - name: Write Inventory
+        run: |
+          printf '[orangepi]\norangepi ansible_host=%s ansible_user=%s\n' \
             "${{ secrets.ANSIBLE_HOST }}" \
             "${{ secrets.ANSIBLE_USER }}" > /tmp/inventory.ini
 

.gitignore

@@ -7,3 +7,8 @@ backend/db/brainwave.db-wal
 node_modules/.vite/vitest/da39a3ee5e6b4b0d3255bfef95601890afd80709/results.json
 brainwave.db-shm
 brainwave.db-wal
+node_modules/
+brainwave.db
+*.db
+*.sqlite
+*.sqlite3

backend/package-lock.json

@@ -14,8 +14,10 @@
         "dotenv": "^16.4.7",
         "express": "^5.1.0",
         "express-rate-limit": "^7.5.0",
+        "helmet": "^8.1.0",
         "jsonwebtoken": "^9.0.2",
         "nodemailer": "^7.0.3",
+        "openai": "^4.95.0",
         "zod": "^3.24.2"
       },
       "devDependencies": {
@@ -954,12 +956,21 @@
       "version": "25.6.0",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-25.6.0.tgz",
       "integrity": "sha512-+qIYRKdNYJwY3vRCZMdJbPLJAtGjQBudzZzdzwQYkEPQd+PJGixUL5QfvCLDaULoLv+RhT3LDkwEfKaAkgSmNQ==",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "undici-types": "~7.19.0"
       }
     },
+    "node_modules/@types/node-fetch": {
+      "version": "2.6.13",
+      "resolved": "https://registry.npmjs.org/@types/node-fetch/-/node-fetch-2.6.13.tgz",
+      "integrity": "sha512-QGpRVpzSaUs30JBSGPjOg4Uveu384erbHBoT1zeONvyCfwQxIkUshLAOqN/k9EjGviPRmWTTe6aH2qySWKTVSw==",
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*",
+        "form-data": "^4.0.4"
+      }
+    },
     "node_modules/@types/nodemailer": {
       "version": "6.4.23",
       "resolved": "https://registry.npmjs.org/@types/nodemailer/-/nodemailer-6.4.23.tgz",
@@ -1118,6 +1129,18 @@
         "url": "https://opencollective.com/vitest"
       }
     },
+    "node_modules/abort-controller": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/abort-controller/-/abort-controller-3.0.0.tgz",
+      "integrity": "sha512-h8lQ8tacZYnR3vNQTgibj+tODHI5/+l06Au2Pcriv/Gmet0eaj4TwWH41sO9wnHDiQsEj19q0drzdWdeAHtweg==",
+      "license": "MIT",
+      "dependencies": {
+        "event-target-shim": "^5.0.0"
+      },
+      "engines": {
+        "node": ">=6.5"
+      }
+    },
     "node_modules/accepts": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-2.0.0.tgz",
@@ -1131,6 +1154,18 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/agentkeepalive": {
+      "version": "4.6.0",
+      "resolved": "https://registry.npmjs.org/agentkeepalive/-/agentkeepalive-4.6.0.tgz",
+      "integrity": "sha512-kja8j7PjmncONqaTsB8fQ+wE2mSU2DJ9D4XKoJ5PFWIdRMa6SLSN1ff4mOr4jCbfRSsxR4keIiySJU0N9T5hIQ==",
+      "license": "MIT",
+      "dependencies": {
+        "humanize-ms": "^1.2.1"
+      },
+      "engines": {
+        "node": ">= 8.0.0"
+      }
+    },
     "node_modules/assertion-error": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-2.0.1.tgz",
@@ -1141,6 +1176,12 @@
         "node": ">=12"
       }
     },
+    "node_modules/asynckit": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
+      "integrity": "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==",
+      "license": "MIT"
+    },
     "node_modules/base64-js": {
       "version": "1.5.1",
       "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-1.5.1.tgz",
@@ -1314,6 +1355,18 @@
       "integrity": "sha512-jJ0bqzaylmJtVnNgzTeSOs8DPavpbYgEr/b0YL8/2GO3xJEhInFmhKMUnEJQjZumK7KXGFhUy89PrsJWlakBVg==",
       "license": "ISC"
     },
+    "node_modules/combined-stream": {
+      "version": "1.0.8",
+      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
+      "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
+      "license": "MIT",
+      "dependencies": {
+        "delayed-stream": "~1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
     "node_modules/content-disposition": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/content-disposition/-/content-disposition-1.1.0.tgz",
@@ -1419,6 +1472,15 @@
         "node": ">=4.0.0"
       }
     },
+    "node_modules/delayed-stream": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
+      "integrity": "sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.4.0"
+      }
+    },
     "node_modules/depd": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/depd/-/depd-2.0.0.tgz",
@@ -1533,6 +1595,21 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/es-set-tostringtag": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/es-set-tostringtag/-/es-set-tostringtag-2.1.0.tgz",
+      "integrity": "sha512-j6vWzfrGVfyXxge+O0x5sh6cvxAog0a/4Rdd2K36zCMV5eJ+/+tOAngRO8cODMNWbVRdVlmGZQL2YS3yR8bIUA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "get-intrinsic": "^1.2.6",
+        "has-tostringtag": "^1.0.2",
+        "hasown": "^2.0.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
     "node_modules/esbuild": {
       "version": "0.27.7",
       "resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.27.7.tgz",
@@ -1600,6 +1677,15 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/event-target-shim": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/event-target-shim/-/event-target-shim-5.0.1.tgz",
+      "integrity": "sha512-i/2XbnSz/uxRCU6+NdVJgKWDTM427+MqYbkQzD321DuCQJUqOuJKIA0IM2+W2xtYHdKOmZ4dR6fExsd4SXL+WQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/expand-template": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/expand-template/-/expand-template-2.0.3.tgz",
@@ -1722,6 +1808,62 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/form-data": {
+      "version": "4.0.5",
+      "resolved": "https://registry.npmjs.org/form-data/-/form-data-4.0.5.tgz",
+      "integrity": "sha512-8RipRLol37bNs2bhoV67fiTEvdTrbMUYcFTiy3+wuuOnUog2QBHCZWXDRijWQfAkhBj2Uf5UnVaiWwA5vdd82w==",
+      "license": "MIT",
+      "dependencies": {
+        "asynckit": "^0.4.0",
+        "combined-stream": "^1.0.8",
+        "es-set-tostringtag": "^2.1.0",
+        "hasown": "^2.0.2",
+        "mime-types": "^2.1.12"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/form-data-encoder": {
+      "version": "1.7.2",
+      "resolved": "https://registry.npmjs.org/form-data-encoder/-/form-data-encoder-1.7.2.tgz",
+      "integrity": "sha512-qfqtYan3rxrnCk1VYaA4H+Ms9xdpPqvLZa6xmMgFvhO32x7/3J/ExcTd6qpxM0vH2GdMI+poehyBZvqfMTto8A==",
+      "license": "MIT"
+    },
+    "node_modules/form-data/node_modules/mime-db": {
+      "version": "1.52.0",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.52.0.tgz",
+      "integrity": "sha512-sPU4uV7dYlvtWJxwwxHD0PuihVNiE7TyAbQ5SWxDCB9mUYvOgroQOwYQQOKPJ8CIbE+1ETVlOoK1UC2nU3gYvg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/form-data/node_modules/mime-types": {
+      "version": "2.1.35",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.35.tgz",
+      "integrity": "sha512-ZDY+bPm5zTTF+YpCrAU9nK0UgICYPT0QtT1NZWFv4s++TNkcgVaT0g6+4R2uI4MjQjzysHB1zxuWL50hzaeXiw==",
+      "license": "MIT",
+      "dependencies": {
+        "mime-db": "1.52.0"
+      },
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/formdata-node": {
+      "version": "4.4.1",
+      "resolved": "https://registry.npmjs.org/formdata-node/-/formdata-node-4.4.1.tgz",
+      "integrity": "sha512-0iirZp3uVDjVGt9p49aTaqjk84TrglENEDuqfdlZQ1roC9CWlPk6Avf8EEnZNcAqPonwkG35x4n3ww/1THYAeQ==",
+      "license": "MIT",
+      "dependencies": {
+        "node-domexception": "1.0.0",
+        "web-streams-polyfill": "4.0.0-beta.3"
+      },
+      "engines": {
+        "node": ">= 12.20"
+      }
+    },
     "node_modules/forwarded": {
       "version": "0.2.0",
       "resolved": "https://registry.npmjs.org/forwarded/-/forwarded-0.2.0.tgz",
@@ -1850,6 +1992,21 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/has-tostringtag": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/has-tostringtag/-/has-tostringtag-1.0.2.tgz",
+      "integrity": "sha512-NqADB8VjPFLM2V0VvHUewwwsw0ZWBaIdgo+ieHtK3hasLz4qeCRjYcqfB6AQrBggRKppKF8L52/VqdVsO47Dlw==",
+      "license": "MIT",
+      "dependencies": {
+        "has-symbols": "^1.0.3"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
     "node_modules/hasown": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/hasown/-/hasown-2.0.3.tgz",
@@ -1862,6 +2019,15 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/helmet": {
+      "version": "8.1.0",
+      "resolved": "https://registry.npmjs.org/helmet/-/helmet-8.1.0.tgz",
+      "integrity": "sha512-jOiHyAZsmnr8LqoPGmCjYAaiuWwjAPLgY8ZX2XrmHawt99/u1y6RgrZMTeoPfpUbV96HOalYgz1qzkRbw54Pmg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18.0.0"
+      }
+    },
     "node_modules/http-errors": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/http-errors/-/http-errors-2.0.1.tgz",
@@ -1882,6 +2048,15 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/humanize-ms": {
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/humanize-ms/-/humanize-ms-1.2.1.tgz",
+      "integrity": "sha512-Fl70vYtsAFb/C06PTS9dZBo7ihau+Tu/DNCk/OyHhea07S+aeMWpFFkUaXRa8fI+ScZbEI8dfSxwY7gxZ9SAVQ==",
+      "license": "MIT",
+      "dependencies": {
+        "ms": "^2.0.0"
+      }
+    },
     "node_modules/iconv-lite": {
       "version": "0.7.2",
       "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.7.2.tgz",
@@ -2444,6 +2619,46 @@
         "node": "^18 || ^20 || >= 21"
       }
     },
+    "node_modules/node-domexception": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/node-domexception/-/node-domexception-1.0.0.tgz",
+      "integrity": "sha512-/jKZoMpw0F8GRwl4/eLROPA3cfcXtLApP0QzLmUT/HuPCZWyB7IY9ZrMeKw2O/nFIqPQB3PVM9aYm0F312AXDQ==",
+      "deprecated": "Use your platform's native DOMException instead",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/jimmywarting"
+        },
+        {
+          "type": "github",
+          "url": "https://paypal.me/jimmywarting"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=10.5.0"
+      }
+    },
+    "node_modules/node-fetch": {
+      "version": "2.7.0",
+      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-2.7.0.tgz",
+      "integrity": "sha512-c4FRfUm/dbcWZ7U+1Wq0AwCyFL+3nt2bEw05wfxSz+DWpWsitgmSgYmy2dQdWyKC1694ELPqMs/YzUSNozLt8A==",
+      "license": "MIT",
+      "dependencies": {
+        "whatwg-url": "^5.0.0"
+      },
+      "engines": {
+        "node": "4.x || >=6.0.0"
+      },
+      "peerDependencies": {
+        "encoding": "^0.1.0"
+      },
+      "peerDependenciesMeta": {
+        "encoding": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/node-gyp-build": {
       "version": "4.8.4",
       "resolved": "https://registry.npmjs.org/node-gyp-build/-/node-gyp-build-4.8.4.tgz",
@@ -2517,6 +2732,51 @@
         "wrappy": "1"
       }
     },
+    "node_modules/openai": {
+      "version": "4.104.0",
+      "resolved": "https://registry.npmjs.org/openai/-/openai-4.104.0.tgz",
+      "integrity": "sha512-p99EFNsA/yX6UhVO93f5kJsDRLAg+CTA2RBqdHK4RtK8u5IJw32Hyb2dTGKbnnFmnuoBv5r7Z2CURI9sGZpSuA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@types/node": "^18.11.18",
+        "@types/node-fetch": "^2.6.4",
+        "abort-controller": "^3.0.0",
+        "agentkeepalive": "^4.2.1",
+        "form-data-encoder": "1.7.2",
+        "formdata-node": "^4.3.2",
+        "node-fetch": "^2.6.7"
+      },
+      "bin": {
+        "openai": "bin/cli"
+      },
+      "peerDependencies": {
+        "ws": "^8.18.0",
+        "zod": "^3.23.8"
+      },
+      "peerDependenciesMeta": {
+        "ws": {
+          "optional": true
+        },
+        "zod": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/openai/node_modules/@types/node": {
+      "version": "18.19.130",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-18.19.130.tgz",
+      "integrity": "sha512-GRaXQx6jGfL8sKfaIDD6OupbIHBr9jv7Jnaml9tB7l4v068PAOXqfcujMMo5PhbIs6ggR1XODELqahT2R8v0fg==",
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~5.26.4"
+      }
+    },
+    "node_modules/openai/node_modules/undici-types": {
+      "version": "5.26.5",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",
+      "integrity": "sha512-JlCMO+ehdEIKqlFxk6IfVoAUVmgz7cU7zD/h9XZ0qzeosSHmUJVOzSQvvYSYWXkFXC+IfLKSIffhv0sVZup6pA==",
+      "license": "MIT"
+    },
     "node_modules/parseurl": {
       "version": "1.3.3",
       "resolved": "https://registry.npmjs.org/parseurl/-/parseurl-1.3.3.tgz",
@@ -3115,6 +3375,12 @@
         "node": ">=0.6"
       }
     },
+    "node_modules/tr46": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/tr46/-/tr46-0.0.3.tgz",
+      "integrity": "sha512-N3WMsuqV66lT30CrXNbEjx4GEwlow3v6rr4mCcv6prnfwhS01rkgyFdjPNBYd9br7LpXV1+Emh01fHnq2Gdgrw==",
+      "license": "MIT"
+    },
     "node_modules/tslib": {
       "version": "2.8.1",
       "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.8.1.tgz",
@@ -3187,7 +3453,6 @@
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       "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.19.2.tgz",
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-      "dev": true,
       "license": "MIT"
     },
     "node_modules/unpipe": {
@@ -3382,6 +3647,31 @@
         }
       }
     },
+    "node_modules/web-streams-polyfill": {
+      "version": "4.0.0-beta.3",
+      "resolved": "https://registry.npmjs.org/web-streams-polyfill/-/web-streams-polyfill-4.0.0-beta.3.tgz",
+      "integrity": "sha512-QW95TCTaHmsYfHDybGMwO5IJIM93I/6vTRk+daHTWFPhwh+C8Cg7j7XyKrwrj8Ib6vYXe0ocYNrmzY4xAAN6ug==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 14"
+      }
+    },
+    "node_modules/webidl-conversions": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
+      "integrity": "sha512-2JAn3z8AR6rjK8Sm8orRC0h/bcl/DqL7tRPdGZ4I1CjdF+EaMLmYxBHyXuKL849eucPFhvBoxMsflfOb8kxaeQ==",
+      "license": "BSD-2-Clause"
+    },
+    "node_modules/whatwg-url": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-5.0.0.tgz",
+      "integrity": "sha512-saE57nupxk6v3HY35+jzBwYa0rKSy0XR8JSxZPwgLr7ys0IBzhGviA1/TUGJLmSVqs8pb9AnvICXEuOHLprYTw==",
+      "license": "MIT",
+      "dependencies": {
+        "tr46": "~0.0.3",
+        "webidl-conversions": "^3.0.0"
+      }
+    },
     "node_modules/why-is-node-running": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/why-is-node-running/-/why-is-node-running-2.3.0.tgz",

backend/package.json

@@ -16,8 +16,10 @@
     "dotenv": "^16.4.7",
     "express": "^5.1.0",
     "express-rate-limit": "^7.5.0",
+    "helmet": "^8.1.0",
     "jsonwebtoken": "^9.0.2",
     "nodemailer": "^7.0.3",
+    "openai": "^4.95.0",
     "zod": "^3.24.2"
   },
   "devDependencies": {

backend/src/config.ts

@@ -26,9 +26,10 @@ export const config = {
   env: env('NODE_ENV', 'development'),
   port: envInt('PORT', 3001),
   jwtSecret: env('JWT_SECRET'),
+  jwtExpiresIn: env('JWT_EXPIRES_IN', '7d'),
   dbPath: env('DB_PATH', './db/brainwave.db'),
   corsOrigin: env('CORS_ORIGIN', 'http://localhost:5173'),
-  bodyLimit: env('BODY_LIMIT', '10mb'),
+  bodyLimit: env('BODY_LIMIT', '100kb'),
 
   email: {
     smtpHost: env('SMTP_HOST', ''),

backend/src/db/database.ts

@@ -4,17 +4,23 @@ import path from 'path'
 import { config } from '../config.js'
 import { runMigrations } from './migrations.js'
 
-const DB_PATH = path.isAbsolute(config.dbPath)
-  ? config.dbPath
-  : path.join(process.cwd(), config.dbPath)
+const DB_PATH = config.dbPath === ':memory:'
+  ? ':memory:'
+  : path.isAbsolute(config.dbPath)
+    ? config.dbPath
+    : path.join(process.cwd(), config.dbPath)
 
 let db: Database.Database | null = null
 
 export function getDb(): Database.Database {
   if (!db) {
-    fs.mkdirSync(path.dirname(DB_PATH), { recursive: true })
+    if (DB_PATH !== ':memory:') {
+      fs.mkdirSync(path.dirname(DB_PATH), { recursive: true })
+    }
     db = new Database(DB_PATH)
-    db.pragma('journal_mode = WAL')
+    if (DB_PATH !== ':memory:') {
+      db.pragma('journal_mode = WAL')
+    }
     db.pragma('foreign_keys = ON')
     runMigrations(db)
   }

backend/src/db/migrations.ts

@@ -49,8 +49,31 @@ export function runMigrations(db: Database.Database): void {
       updated_at INTEGER DEFAULT (unixepoch())
     );
 
+    CREATE TABLE IF NOT EXISTS ai_usage_daily (
+      user_id       INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+      period_date   TEXT NOT NULL,
+      tokens_used   INTEGER NOT NULL DEFAULT 0,
+      requests_used INTEGER NOT NULL DEFAULT 0,
+      updated_at    INTEGER DEFAULT (unixepoch()),
+      PRIMARY KEY (user_id, period_date)
+    );
+
     CREATE INDEX IF NOT EXISTS idx_saved_exams_user ON saved_exams(user_id);
     CREATE INDEX IF NOT EXISTS idx_exam_results_user ON exam_results(user_id);
+    CREATE INDEX IF NOT EXISTS idx_ai_usage_daily_user ON ai_usage_daily(user_id);
+  `);
+
+  // ── Add share_token and is_public columns if missing ──
+  const examCols = db.prepare(`PRAGMA table_info(saved_exams)`).all() as { name: string }[];
+  if (!examCols.some((c) => c.name === 'share_token')) {
+    db.exec(`ALTER TABLE saved_exams ADD COLUMN share_token TEXT`);
+  }
+  if (!examCols.some((c) => c.name === 'is_public')) {
+    db.exec(`ALTER TABLE saved_exams ADD COLUMN is_public INTEGER DEFAULT 0`);
+  }
+
+  db.exec(`
+    CREATE UNIQUE INDEX IF NOT EXISTS idx_saved_exams_share ON saved_exams(share_token);
   `);
 
   // ── Add role column if missing (existing databases) ──
@@ -61,15 +84,58 @@ export function runMigrations(db: Database.Database): void {
     db.exec(`ALTER TABLE users ADD COLUMN role TEXT NOT NULL DEFAULT 'user'`);
   }
 
-  // ── Promote first user to admin if no admins exist ──
-  const adminCount = db
-    .prepare(`SELECT COUNT(*) AS cnt FROM users WHERE role = 'admin'`)
-    .get() as { cnt: number };
-  if (adminCount.cnt === 0) {
-    db.prepare(
-      `UPDATE users SET role = 'admin' WHERE id = (SELECT MIN(id) FROM users)`,
-    ).run();
-  }
+    // ── Add storage_quota_bytes if missing ──
+    if (!cols.some((c) => c.name === "storage_quota_bytes")) {
+      db.exec(`ALTER TABLE users ADD COLUMN storage_quota_bytes INTEGER NOT NULL DEFAULT 1073741824`);
+    }
+
+    // ── Add plan if missing ──
+    if (!cols.some((c) => c.name === "plan")) {
+      db.exec(`ALTER TABLE users ADD COLUMN plan TEXT NOT NULL DEFAULT 'free'`);
+    }
+
+    // ── Add token_version if missing (JWT revocation on password change/reset) ──
+    if (!cols.some((c) => c.name === "token_version")) {
+      db.exec(`ALTER TABLE users ADD COLUMN token_version INTEGER NOT NULL DEFAULT 0`);
+    }
+
+    // ── Add is_favorite to saved_exams if missing ──
+    const examSavedCols = db.prepare(`PRAGMA table_info(saved_exams)`).all() as { name: string }[];
+    if (!examSavedCols.some((c) => c.name === 'is_favorite')) {
+      db.exec(`ALTER TABLE saved_exams ADD COLUMN is_favorite INTEGER DEFAULT 0`);
+    }
+
+    // ── Add tags to saved_exams if missing ──
+    if (!examSavedCols.some((c) => c.name === 'tags')) {
+      db.exec(`ALTER TABLE saved_exams ADD COLUMN tags TEXT DEFAULT '[]'`);
+    }
+
+    // ── Add collection_id to saved_exams if missing ──
+    if (!examSavedCols.some((c) => c.name === 'collection_id')) {
+      db.exec(`ALTER TABLE saved_exams ADD COLUMN collection_id INTEGER REFERENCES collections(id) ON DELETE SET NULL`);
+    }
+
+    // ── Add share_mode to saved_exams if missing ──
+    if (!examSavedCols.some((c) => c.name === 'share_mode')) {
+      db.exec(`ALTER TABLE saved_exams ADD COLUMN share_mode TEXT DEFAULT 'clone'`);
+    }
+
+    // ── Add cloned_from_share_token to saved_exams if missing ──
+    if (!examSavedCols.some((c) => c.name === 'cloned_from_share_token')) {
+      db.exec(`ALTER TABLE saved_exams ADD COLUMN cloned_from_share_token TEXT`);
+    }
+
+    // ── Collections table ──
+    db.exec(`
+      CREATE TABLE IF NOT EXISTS collections (
+        id          INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id     INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+        name        TEXT NOT NULL,
+        created_at  INTEGER DEFAULT (unixepoch()),
+        updated_at  INTEGER DEFAULT (unixepoch())
+      );
+      CREATE INDEX IF NOT EXISTS idx_collections_user ON collections(user_id);
+    `);
 
   // ── Seed default settings ──
   const defaults: Record<string, string> = {
@@ -88,6 +154,16 @@ export function runMigrations(db: Database.Database): void {
     smtp_from: "BrainWave <noreply@brainwave.local>",
     smtp_secure: "auto",
     app_url: "http://localhost:5173",
+    ai_provider: "",
+    ai_model: "gpt-4o-mini",
+    ai_api_key: "",
+    ai_base_url: "",
+    ai_model_hint: "",
+    ai_model_generate: "",
+    ai_model_grading: "",
+    ai_model_tutor: "",
+    ai_model_study_coach: "",
+    ai_daily_token_limit: "0",
   };
   const upsert = db.prepare(`
     INSERT INTO site_settings (key, value) VALUES (?, ?)

backend/src/index.ts

@@ -1,12 +1,18 @@
 import 'dotenv/config'
 import express from 'express'
 import cors from 'cors'
+import helmet from 'helmet'
+import rateLimit from 'express-rate-limit'
 import { getDb, closeDb } from './db/database.js'
 import authRoutes from './routes/auth.js'
 import examRoutes from './routes/exams.js'
 import resultRoutes from './routes/results.js'
 import adminRoutes from './routes/admin.js'
 import setupRoutes from './routes/setup.js'
+import gradeRoutes from './routes/grade.js'
+import shareRoutes from './routes/share.js'
+import collectionRoutes from './routes/collections.js'
+import aiRoutes from './routes/ai.js'
 import { errorHandler } from './middleware/error.js'
 import { config } from './config.js'
 import path from 'path'
@@ -20,9 +26,25 @@ const PORT = config.port
 
 const app = express()
 
+// Security headers
+app.use(helmet())
+
+// CORS
 app.use(cors({ origin: config.corsOrigin }))
+
+// Body parsing with reasonable limit
 app.use(express.json({ limit: config.bodyLimit }))
 
+// Global API rate limiting
+const globalLimiter = rateLimit({
+  windowMs: 15 * 60 * 1000, // 15 minutes
+  max: 200,
+  message: { error: 'Too many requests, please try again later' },
+  standardHeaders: true,
+  legacyHeaders: false,
+})
+app.use('/api/', globalLimiter)
+
 // Request logging
 app.use((req, res, next) => {
   const start = Date.now()
@@ -42,7 +64,11 @@ app.use('/api/setup', setupRoutes)
 app.use('/api/auth', authRoutes)
 app.use('/api/exams', examRoutes)
 app.use('/api/results', resultRoutes)
+app.use('/api/grade', gradeRoutes)
+app.use('/api/ai', aiRoutes)
 app.use('/api/admin', adminRoutes)
+app.use('/api/share', shareRoutes)
+app.use('/api/collections', collectionRoutes)
 
 // Health check with subsystem status
 app.get('/api/health', (_req, res) => {
@@ -63,7 +89,6 @@ app.get('/api/health', (_req, res) => {
   res.status(overall === 'healthy' ? 200 : 503).json({
     status: overall,
     timestamp: Date.now(),
-    version: process.env['npm_package_version'] ?? '0.0.1',
     checks,
   })
 })

backend/src/middleware/auth.test.ts

@@ -0,0 +1,127 @@
+import { describe, it, expect, vi } from 'vitest'
+import type { Request, Response, NextFunction } from 'express'
+import * as userRepo from '../repositories/userRepo.js'
+import { signToken } from '../utils/tokens.js'
+import { requireAuth } from './auth.js'
+
+function mockRes(): Response {
+  const res = {} as Response
+  res.status = vi.fn(() => res) as unknown as Response['status']
+  res.json = vi.fn(() => res) as unknown as Response['json']
+  return res
+}
+
+function makeReq(token?: string): Request {
+  const headers: Record<string, string> = {}
+  if (token) headers.authorization = `Bearer ${token}`
+  return { headers } as unknown as Request
+}
+
+function createUser(role: 'user' | 'admin' = 'user'): { id: number; email: string; name: string } {
+  const email = `user-${Math.random().toString(36).slice(2)}@example.com`
+  const { id } = userRepo.createUser({
+    email,
+    passwordHash: 'x',
+    displayName: 'Test User',
+    role,
+    emailVerified: 1,
+  })
+  return { id, email, name: 'Test User' }
+}
+
+describe('requireAuth', () => {
+  it('accepts a valid token and loads fresh user data from the DB', () => {
+    const u = createUser()
+    const token = signToken({ userId: u.id, email: u.email, displayName: u.name, role: 'user', tv: 0 })
+    const req = makeReq(token)
+    const res = mockRes()
+    const next = vi.fn() as NextFunction
+
+    requireAuth(req, res, next)
+
+    expect(next).toHaveBeenCalledOnce()
+    expect(res.status).not.toHaveBeenCalled()
+    expect(req.user?.userId).toBe(u.id)
+    expect(req.user?.role).toBe('user')
+    expect(req.user?.tv).toBe(0)
+  })
+
+  it('serves the current DB role, not the role claimed by an old JWT', () => {
+    const u = createUser()
+    // Token signed while the user was still an admin
+    const staleAdminToken = signToken({ userId: u.id, email: u.email, displayName: u.name, role: 'admin', tv: 0 })
+    userRepo.updateUser(u.id, { role: 'user' })
+    const req = makeReq(staleAdminToken)
+    const res = mockRes()
+    const next = vi.fn() as NextFunction
+
+    requireAuth(req, res, next)
+
+    expect(next).toHaveBeenCalledOnce()
+    expect(req.user?.role).toBe('user')
+  })
+
+  it('rejects tokens for deleted accounts', () => {
+    const u = createUser()
+    const token = signToken({ userId: u.id, email: u.email, displayName: u.name, role: 'user', tv: 0 })
+    userRepo.deleteUser(u.id)
+    const req = makeReq(token)
+    const res = mockRes()
+    const next = vi.fn() as NextFunction
+
+    requireAuth(req, res, next)
+
+    expect(next).not.toHaveBeenCalled()
+    expect(res.status).toHaveBeenCalledWith(401)
+  })
+
+  it('rejects tokens whose token version is stale (e.g. after password change)', () => {
+    const u = createUser()
+    const oldToken = signToken({ userId: u.id, email: u.email, displayName: u.name, role: 'user', tv: 0 })
+    userRepo.updateUser(u.id, { tokenVersion: 1 })
+    const req = makeReq(oldToken)
+    const res = mockRes()
+    const next = vi.fn() as NextFunction
+
+    requireAuth(req, res, next)
+
+    expect(next).not.toHaveBeenCalled()
+    expect(res.status).toHaveBeenCalledWith(401)
+  })
+
+  it('accepts a token signed with the current token version after rotation', () => {
+    const u = createUser()
+    userRepo.updateUser(u.id, { tokenVersion: 2 })
+    const freshToken = signToken({ userId: u.id, email: u.email, displayName: u.name, role: 'user', tv: 2 })
+    const req = makeReq(freshToken)
+    const res = mockRes()
+    const next = vi.fn() as NextFunction
+
+    requireAuth(req, res, next)
+
+    expect(next).toHaveBeenCalledOnce()
+    expect(req.user?.tv).toBe(2)
+  })
+
+  it('rejects requests without a Bearer header', () => {
+    const req = makeReq()
+    const res = mockRes()
+    const next = vi.fn() as NextFunction
+
+    requireAuth(req, res, next)
+
+    expect(next).not.toHaveBeenCalled()
+    expect(res.status).toHaveBeenCalledWith(401)
+  })
+
+  it('rejects garbage tokens', () => {
+    const req = makeReq('not.a.jwt')
+    const res = mockRes()
+    const next = vi.fn() as NextFunction
+
+    requireAuth(req, res, next)
+
+    expect(next).not.toHaveBeenCalled()
+    expect(res.status).toHaveBeenCalledWith(401)
+  })
+})

backend/src/middleware/auth.ts

@@ -1,5 +1,7 @@
 import type { Request, Response, NextFunction } from 'express'
-import { verifyToken, type JwtPayload } from '../utils/tokens.js'
+import { verifyToken, hashToken, type JwtPayload } from '../utils/tokens.js'
+import { isTokenBlacklisted } from '../utils/tokenBlacklist.js'
+import { getUserById } from '../repositories/userRepo.js'
 
 declare global {
   namespace Express {
@@ -21,7 +23,34 @@ export function requireAuth(req: Request, res: Response, next: NextFunction): vo
   }
   try {
     const token = header.slice(7)
-    req.user = verifyToken(token)
+    const payload = verifyToken(token)
+
+    // Check if the token has been blacklisted (e.g., after logout)
+    if (isTokenBlacklisted(hashToken(token))) {
+      res.status(401).json({ error: 'Token has been revoked' })
+      return
+    }
+
+    // Revalidate against the database: deleted accounts must not keep working,
+    // and role/token-version must come from the DB rather than an old JWT claim
+    // (revocation after demotion or password change/reset).
+    const user = getUserById(payload.userId)
+    if (!user) {
+      res.status(401).json({ error: 'Account no longer exists' })
+      return
+    }
+    if ((user.token_version ?? 0) !== payload.tv) {
+      res.status(401).json({ error: 'Session expired, please sign in again' })
+      return
+    }
+
+    req.user = {
+      userId: user.id,
+      email: user.email,
+      displayName: user.display_name,
+      role: user.role,
+      tv: payload.tv,
+    }
     next()
   } catch {
     res.status(401).json({ error: 'Invalid or expired token' })

backend/src/middleware/error.ts

@@ -17,15 +17,21 @@ export function errorHandler(
   _next: any
 ) {
   const statusCode = err instanceof AppError ? err.statusCode : 500;
-  const message = err.message || 'Internal Server Error';
+  const isOperational = err instanceof AppError && err.isOperational;
 
-  console.error(`[Error] ${statusCode} - ${message}`);
-  if (!(err instanceof AppError) || !err.isOperational) {
+  // Log full details server-side
+  console.error(`[Error] ${statusCode} - ${err.message}`);
+  if (!isOperational) {
     console.error(err);
   }
 
+  // Never leak internal error details to the client for unexpected 500s
+  const clientMessage = statusCode === 500 && !isOperational
+    ? 'Internal Server Error'
+    : (err.message || 'Internal Server Error');
+
   res.status(statusCode).json({
     status: 'error',
-    message,
+    message: clientMessage,
   });
-}
+}

backend/src/repositories/aiUsageRepo.ts

@@ -0,0 +1,46 @@
+import { getDb } from '../db/database.js'
+
+export interface AiDailyUsage {
+  tokensUsed: number
+  requestsUsed: number
+}
+
+function normalizeCount(value: number): number {
+  if (!Number.isFinite(value) || value <= 0) return 0
+  return Math.floor(value)
+}
+
+export function getDailyUsage(userId: number, periodDate: string): AiDailyUsage {
+  const db = getDb()
+  const row = db.prepare(`
+    SELECT tokens_used, requests_used
+    FROM ai_usage_daily
+    WHERE user_id = ? AND period_date = ?
+  `).get(userId, periodDate) as { tokens_used: number; requests_used: number } | undefined
+
+  return {
+    tokensUsed: row?.tokens_used ?? 0,
+    requestsUsed: row?.requests_used ?? 0,
+  }
+}
+
+export function incrementDailyUsage(
+  userId: number,
+  periodDate: string,
+  tokensUsed: number,
+  requestsUsed = 1,
+): void {
+  const db = getDb()
+  const tokens = normalizeCount(tokensUsed)
+  const requests = normalizeCount(requestsUsed)
+  if (tokens === 0 && requests === 0) return
+
+  db.prepare(`
+    INSERT INTO ai_usage_daily (user_id, period_date, tokens_used, requests_used)
+    VALUES (?, ?, ?, ?)
+    ON CONFLICT(user_id, period_date) DO UPDATE SET
+      tokens_used = tokens_used + excluded.tokens_used,
+      requests_used = requests_used + excluded.requests_used,
+      updated_at = unixepoch()
+  `).run(userId, periodDate, tokens, requests)
+}

backend/src/repositories/collectionRepo.ts

@@ -0,0 +1,55 @@
+import { getDb } from '../db/database.js'
+
+export interface DbCollection {
+  id: number
+  user_id: number
+  name: string
+  created_at: number
+  updated_at: number
+}
+
+export interface CollectionWithCount extends DbCollection {
+  exam_count: number
+}
+
+export function createCollection(userId: number, name: string): { id: number } {
+  const db = getDb()
+  const result = db.prepare(`
+    INSERT INTO collections (user_id, name)
+    VALUES (?, ?)
+  `).run(userId, name)
+  return { id: result.lastInsertRowid as number }
+}
+
+export function getCollectionById(id: number, userId: number): DbCollection | undefined {
+  const db = getDb()
+  return db.prepare('SELECT * FROM collections WHERE id = ? AND user_id = ?').get(id, userId) as DbCollection | undefined
+}
+
+export function listCollectionsByUser(userId: number): CollectionWithCount[] {
+  const db = getDb()
+  return db.prepare(`
+    SELECT c.*, COUNT(se.id) AS exam_count
+    FROM collections c
+    LEFT JOIN saved_exams se ON se.collection_id = c.id
+    WHERE c.user_id = ?
+    GROUP BY c.id
+    ORDER BY c.updated_at DESC
+  `).all(userId) as CollectionWithCount[]
+}
+
+export function updateCollection(id: number, userId: number, name: string): boolean {
+  const db = getDb()
+  const result = db.prepare(`
+    UPDATE collections
+    SET name = ?, updated_at = unixepoch()
+    WHERE id = ? AND user_id = ?
+  `).run(name, id, userId)
+  return result.changes > 0
+}
+
+export function deleteCollection(id: number, userId: number): boolean {
+  const db = getDb()
+  const result = db.prepare('DELETE FROM collections WHERE id = ? AND user_id = ?').run(id, userId)
+  return result.changes > 0
+}

backend/src/repositories/examRepo.ts

@@ -8,6 +8,12 @@ export interface DbExam {
   exam_json: string
   created_at: number
   updated_at: number
+  share_token: string | null
+  is_public: number
+  is_favorite: number
+  tags: string | null
+  share_mode: string | null
+  cloned_from_share_token: string | null
 }
 
 export interface ExamListItem {
@@ -17,14 +23,18 @@ export interface ExamListItem {
   created_at: number
   updated_at: number
   question_count: number
+  share_token: string | null
+  is_favorite: number
+  tags: string
+  collection_id: number | null
 }
 
-export function createExam(userId: number, title: string, subtitle: string | null, examJson: string): { id: number } {
+export function createExam(userId: number, title: string, subtitle: string | null, examJson: string, tagsJson: string = '[]'): { id: number } {
   const db = getDb()
   const result = db.prepare(`
-    INSERT INTO saved_exams (user_id, title, subtitle, exam_json)
-    VALUES (?, ?, ?, ?)
-  `).run(userId, title, subtitle, examJson)
+    INSERT INTO saved_exams (user_id, title, subtitle, exam_json, tags)
+    VALUES (?, ?, ?, ?, ?)
+  `).run(userId, title, subtitle, examJson, tagsJson)
   return { id: result.lastInsertRowid as number }
 }
 
@@ -36,16 +46,24 @@ export function getExamById(id: number, userId: number): DbExam | undefined {
 export function listExamsByUser(userId: number): ExamListItem[] {
   const db = getDb()
   return db.prepare(`
-    SELECT id, title, subtitle, created_at, updated_at,
+    SELECT id, title, subtitle, created_at, updated_at, share_token, is_favorite, tags, collection_id,
            json_array_length(json_extract(exam_json, '$.questions')) AS question_count
     FROM saved_exams
     WHERE user_id = ?
-    ORDER BY updated_at DESC
+    ORDER BY is_favorite DESC, updated_at DESC
   `).all(userId) as ExamListItem[]
 }
 
-export function updateExam(id: number, userId: number, title: string, subtitle: string | null, examJson: string): boolean {
+export function updateExam(id: number, userId: number, title: string, subtitle: string | null, examJson: string, tagsJson: string | null = null): boolean {
   const db = getDb()
+  if (tagsJson !== null) {
+    const result = db.prepare(`
+      UPDATE saved_exams
+      SET title = ?, subtitle = ?, exam_json = ?, tags = ?, updated_at = unixepoch()
+      WHERE id = ? AND user_id = ?
+    `).run(title, subtitle, examJson, tagsJson, id, userId)
+    return result.changes > 0
+  }
   const result = db.prepare(`
     UPDATE saved_exams
     SET title = ?, subtitle = ?, exam_json = ?, updated_at = unixepoch()
@@ -65,3 +83,106 @@ export function countExams(): number {
   const row = db.prepare('SELECT COUNT(*) AS cnt FROM saved_exams').get() as { cnt: number }
   return row.cnt
 }
+
+export function setShareToken(id: number, userId: number, token: string, mode: string = 'clone'): boolean {
+  const db = getDb()
+  const result = db.prepare(`
+    UPDATE saved_exams
+    SET share_token = ?, is_public = 1, share_mode = ?, updated_at = unixepoch()
+    WHERE id = ? AND user_id = ?
+  `).run(token, mode, id, userId)
+  return result.changes > 0
+}
+
+export function clearShareToken(id: number, userId: number): boolean {
+  const db = getDb()
+  const result = db.prepare(`
+    UPDATE saved_exams
+    SET share_token = NULL, is_public = 0, share_mode = 'clone', updated_at = unixepoch()
+    WHERE id = ? AND user_id = ?
+  `).run(id, userId)
+  return result.changes > 0
+}
+
+export function getExamByShareToken(token: string): DbExam | undefined {
+  const db = getDb()
+  return db.prepare('SELECT * FROM saved_exams WHERE share_token = ? AND is_public = 1').get(token) as DbExam | undefined
+}
+
+export function setShareMode(id: number, userId: number, mode: string): boolean {
+  const db = getDb()
+  const result = db.prepare(`
+    UPDATE saved_exams
+    SET share_mode = ?, updated_at = unixepoch()
+    WHERE id = ? AND user_id = ?
+  `).run(mode, id, userId)
+  return result.changes > 0
+}
+
+export function cloneExam(userId: number, sourceExam: DbExam, shareToken: string): { id: number } {
+  const db = getDb()
+  const parsed = JSON.parse(sourceExam.exam_json)
+  parsed.id = undefined
+  const result = db.prepare(`
+    INSERT INTO saved_exams (user_id, title, subtitle, exam_json, cloned_from_share_token)
+    VALUES (?, ?, ?, ?, ?)
+  `).run(userId, sourceExam.title + ' (copy)', sourceExam.subtitle, JSON.stringify(parsed), shareToken)
+  return { id: result.lastInsertRowid as number }
+}
+
+export interface ClonedExamItem {
+  id: number
+  title: string
+  subtitle: string | null
+  created_at: number
+  updated_at: number
+  question_count: number
+  cloned_from_share_token: string
+}
+
+export function listClonedExams(userId: number): ClonedExamItem[] {
+  const db = getDb()
+  return db.prepare(`
+    SELECT id, title, subtitle, created_at, updated_at, cloned_from_share_token,
+           json_array_length(json_extract(exam_json, '$.questions')) AS question_count
+    FROM saved_exams
+    WHERE user_id = ? AND cloned_from_share_token IS NOT NULL
+    ORDER BY updated_at DESC
+  `).all(userId) as ClonedExamItem[]
+}
+
+export function setFavorite(id: number, userId: number, isFavorite: boolean): boolean {
+  const db = getDb()
+  const result = db.prepare(`
+    UPDATE saved_exams
+    SET is_favorite = ?, updated_at = unixepoch()
+    WHERE id = ? AND user_id = ?
+  `).run(isFavorite ? 1 : 0, id, userId)
+  return result.changes > 0
+}
+
+export function getExamRawJson(id: number, userId: number): { title: string; exam_json: string } | undefined {
+  const db = getDb()
+  return db.prepare('SELECT title, exam_json FROM saved_exams WHERE id = ? AND user_id = ?').get(id, userId) as { title: string; exam_json: string } | undefined
+}
+
+export function duplicateOwnExam(userId: number, sourceExam: DbExam): { id: number } {
+  const db = getDb()
+  const parsed = JSON.parse(sourceExam.exam_json)
+  parsed.id = undefined
+  const result = db.prepare(`
+    INSERT INTO saved_exams (user_id, title, subtitle, exam_json, tags)
+    VALUES (?, ?, ?, ?, ?)
+  `).run(userId, sourceExam.title + ' (copy)', sourceExam.subtitle, JSON.stringify(parsed), sourceExam.tags ?? '[]')
+  return { id: result.lastInsertRowid as number }
+}
+
+export function setExamCollection(id: number, userId: number, collectionId: number | null): boolean {
+  const db = getDb()
+  const result = db.prepare(`
+    UPDATE saved_exams
+    SET collection_id = ?, updated_at = unixepoch()
+    WHERE id = ? AND user_id = ?
+  `).run(collectionId, id, userId)
+  return result.changes > 0
+}

backend/src/repositories/resultRepo.ts

@@ -110,3 +110,62 @@ export function countResultsByUser(userId: number): number {
   const row = db.prepare('SELECT COUNT(*) AS cnt FROM exam_results WHERE user_id = ?').get(userId) as { cnt: number }
   return row.cnt
 }
+
+export function getResultsWithExamJson(userId: number, limit = 100): Array<{
+  title: string
+  score_points: number
+  total_points: number
+  correct_count: number
+  graded_count: number
+  completed_at: number
+  exam_json: string
+  exam_id: number | null
+}> {
+  const db = getDb()
+  return db.prepare(`
+    SELECT title, score_points, total_points, correct_count, graded_count, completed_at, exam_json, exam_id
+    FROM exam_results
+    WHERE user_id = ?
+    ORDER BY completed_at DESC
+    LIMIT ?
+  `).all(userId, limit) as Array<{
+    title: string
+    score_points: number
+    total_points: number
+    correct_count: number
+    graded_count: number
+    completed_at: number
+    exam_json: string
+    exam_id: number | null
+  }>
+}
+
+export interface ScoreTrend {
+  completed_at: number
+  score_pct: number
+  title: string
+  exam_id: number | null
+}
+
+export function getScoreTrends(userId: number, limit = 30): Array<{
+  completed_at: number
+  score_points: number
+  total_points: number
+  title: string
+  exam_id: number | null
+}> {
+  const db = getDb()
+  return db.prepare(`
+    SELECT completed_at, score_points, total_points, title, exam_id
+    FROM exam_results
+    WHERE user_id = ? AND total_points > 0
+    ORDER BY completed_at ASC
+    LIMIT ?
+  `).all(userId, limit) as Array<{
+    completed_at: number
+    score_points: number
+    total_points: number
+    title: string
+    exam_id: number | null
+  }>
+}

backend/src/repositories/storageRepo.test.ts

@@ -0,0 +1,157 @@
+import { describe, it, expect } from 'vitest'
+
+// Set env vars before any module that reads them at import time
+process.env.JWT_SECRET = process.env.JWT_SECRET || 'test-secret-for-unit-tests-only'
+process.env.DB_PATH = ':memory:'
+
+// Dynamic imports ensure env vars are set before module initialisation
+const { getDb, closeDb } = await import('../db/database.js')
+const userRepo = await import('./userRepo.js')
+const storageRepo = await import('./storageRepo.js')
+
+describe('storageRepo', () => {
+  it('returns zero usage for a new user', () => {
+    const { id: userId } = userRepo.createUser({
+      email: 'storage-test@example.com',
+      passwordHash: 'hash',
+      displayName: 'Storage Test',
+      emailVerified: 1,
+    })
+
+    const usage = storageRepo.getUserStorageUsage(userId)
+    expect(usage.usedBytes).toBe(0)
+    expect(usage.examBytes).toBe(0)
+    expect(usage.resultBytes).toBe(0)
+  })
+
+  it('calculates exam JSON length correctly', () => {
+    const { id: userId } = userRepo.createUser({
+      email: 'storage-exam@example.com',
+      passwordHash: 'hash',
+      displayName: 'Exam Storage',
+      emailVerified: 1,
+    })
+
+    const db = getDb()
+    const examJson = JSON.stringify({ title: 'Test Exam', questions: [] })
+    db.prepare(`
+      INSERT INTO saved_exams (user_id, title, exam_json)
+      VALUES (?, ?, ?)
+    `).run(userId, 'Test Exam', examJson)
+
+    const usage = storageRepo.getUserStorageUsage(userId)
+    expect(usage.examBytes).toBe(examJson.length)
+    expect(usage.usedBytes).toBe(examJson.length)
+  })
+
+  it('calculates result JSON length correctly', () => {
+    const { id: userId } = userRepo.createUser({
+      email: 'storage-result@example.com',
+      passwordHash: 'hash',
+      displayName: 'Result Storage',
+      emailVerified: 1,
+    })
+
+    const db = getDb()
+    const stateJson = JSON.stringify({ answers: [1, 2, 3] })
+    const examJson = JSON.stringify({ title: 'Result Exam' })
+    db.prepare(`
+      INSERT INTO exam_results
+      (user_id, title, score_points, total_points, correct_count, graded_count, elapsed_ms, state_json, exam_json)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+    `).run(userId, 'Result Exam', 10, 20, 5, 10, 60000, stateJson, examJson)
+
+    const usage = storageRepo.getUserStorageUsage(userId)
+    expect(usage.resultBytes).toBe(stateJson.length + examJson.length)
+    expect(usage.usedBytes).toBe(stateJson.length + examJson.length)
+  })
+
+  it('aggregates multiple exams and results', () => {
+    const { id: userId } = userRepo.createUser({
+      email: 'storage-multi@example.com',
+      passwordHash: 'hash',
+      displayName: 'Multi Storage',
+      emailVerified: 1,
+    })
+
+    const db = getDb()
+    const examJson1 = JSON.stringify({ title: 'Exam 1' })
+    const examJson2 = JSON.stringify({ title: 'Exam 2', extra: 'data' })
+
+    db.prepare(`INSERT INTO saved_exams (user_id, title, exam_json) VALUES (?, ?, ?)`)
+      .run(userId, 'Exam 1', examJson1)
+    db.prepare(`INSERT INTO saved_exams (user_id, title, exam_json) VALUES (?, ?, ?)`)
+      .run(userId, 'Exam 2', examJson2)
+
+    const stateJson = JSON.stringify({ answers: [] })
+    db.prepare(`
+      INSERT INTO exam_results
+      (user_id, title, score_points, total_points, correct_count, graded_count, elapsed_ms, state_json, exam_json)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+    `).run(userId, 'Result', 5, 10, 3, 5, 30000, stateJson, examJson1)
+
+    const usage = storageRepo.getUserStorageUsage(userId)
+    expect(usage.examBytes).toBe(examJson1.length + examJson2.length)
+    expect(usage.resultBytes).toBe(stateJson.length + examJson1.length)
+    expect(usage.usedBytes).toBe(examJson1.length + examJson2.length + stateJson.length + examJson1.length)
+  })
+
+  it('lists storage items sorted by size desc', () => {
+    const { id: userId } = userRepo.createUser({
+      email: 'storage-items@example.com',
+      passwordHash: 'hash',
+      displayName: 'Items Storage',
+      emailVerified: 1,
+    })
+
+    const db = getDb()
+    const smallExam = JSON.stringify({ title: 'Small' })
+    const largeExam = JSON.stringify({ title: 'Large Exam', content: 'x'.repeat(100) })
+    const stateJson = JSON.stringify({ a: 'y'.repeat(50) })
+
+    db.prepare(`INSERT INTO saved_exams (user_id, title, exam_json) VALUES (?, ?, ?)`)
+      .run(userId, 'Small Exam', smallExam)
+    db.prepare(`INSERT INTO saved_exams (user_id, title, exam_json) VALUES (?, ?, ?)`)
+      .run(userId, 'Large Exam', largeExam)
+    db.prepare(`
+      INSERT INTO exam_results
+      (user_id, title, score_points, total_points, correct_count, graded_count, elapsed_ms, state_json, exam_json)
+      VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+    `).run(userId, 'Result', 5, 10, 3, 5, 30000, stateJson, smallExam)
+
+    const items = storageRepo.listStorageItems(userId)
+    expect(items.length).toBe(3)
+    expect(items[0].title).toBe('Large Exam')
+    expect(items[0].type).toBe('exam')
+    expect(items[1].title).toBe('Result')
+    expect(items[1].type).toBe('result')
+    expect(items[2].title).toBe('Small Exam')
+    expect(items[2].type).toBe('exam')
+  })
+
+  it('does not include other users data', () => {
+    const { id: userA } = userRepo.createUser({
+      email: 'user-a@example.com',
+      passwordHash: 'hash',
+      displayName: 'User A',
+      emailVerified: 1,
+    })
+    const { id: userB } = userRepo.createUser({
+      email: 'user-b@example.com',
+      passwordHash: 'hash',
+      displayName: 'User B',
+      emailVerified: 1,
+    })
+
+    const db = getDb()
+    const examJson = JSON.stringify({ title: 'A Exam' })
+    db.prepare(`INSERT INTO saved_exams (user_id, title, exam_json) VALUES (?, ?, ?)`)
+      .run(userA, 'A Exam', examJson)
+
+    const usageA = storageRepo.getUserStorageUsage(userA)
+    const usageB = storageRepo.getUserStorageUsage(userB)
+
+    expect(usageA.usedBytes).toBe(examJson.length)
+    expect(usageB.usedBytes).toBe(0)
+  })
+})

backend/src/repositories/storageRepo.ts

@@ -0,0 +1,61 @@
+import { getDb } from '../db/database.js'
+
+export interface StorageUsage {
+  usedBytes: number
+  examBytes: number
+  resultBytes: number
+}
+
+export interface StorageItem {
+  id: number
+  title: string
+  type: 'exam' | 'result'
+  sizeBytes: number
+  createdAt: number
+}
+
+export function getUserStorageUsage(userId: number): StorageUsage {
+  const db = getDb()
+  const examRow = db.prepare(`
+    SELECT COALESCE(SUM(LENGTH(exam_json)), 0) AS total
+    FROM saved_exams
+    WHERE user_id = ?
+  `).get(userId) as { total: number }
+
+  const resultRow = db.prepare(`
+    SELECT COALESCE(SUM(LENGTH(state_json) + LENGTH(exam_json)), 0) AS total
+    FROM exam_results
+    WHERE user_id = ?
+  `).get(userId) as { total: number }
+
+  return {
+    usedBytes: examRow.total + resultRow.total,
+    examBytes: examRow.total,
+    resultBytes: resultRow.total,
+  }
+}
+
+export function listStorageItems(userId: number): StorageItem[] {
+  const db = getDb()
+  const exams = db.prepare(`
+    SELECT id, title, LENGTH(exam_json) AS size_bytes, created_at
+    FROM saved_exams
+    WHERE user_id = ?
+    ORDER BY size_bytes DESC
+  `).all(userId) as { id: number; title: string; size_bytes: number; created_at: number }[]
+
+  const results = db.prepare(`
+    SELECT id, title, LENGTH(state_json) + LENGTH(exam_json) AS size_bytes, completed_at AS created_at
+    FROM exam_results
+    WHERE user_id = ?
+    ORDER BY size_bytes DESC
+  `).all(userId) as { id: number; title: string; size_bytes: number; created_at: number }[]
+
+  const items: StorageItem[] = [
+    ...exams.map((e) => ({ id: e.id, title: e.title, type: 'exam' as const, sizeBytes: e.size_bytes, createdAt: e.created_at })),
+    ...results.map((r) => ({ id: r.id, title: r.title, type: 'result' as const, sizeBytes: r.size_bytes, createdAt: r.created_at })),
+  ]
+
+  items.sort((a, b) => b.sizeBytes - a.sizeBytes)
+  return items
+}

backend/src/repositories/userRepo.test.ts

@@ -0,0 +1,47 @@
+import { describe, it, expect } from 'vitest'
+import * as userRepo from './userRepo.js'
+
+function uniqueEmail(): string {
+  return `safe-${Math.random().toString(36).slice(2)}@example.com`
+}
+
+describe('userRepo.listUsers', () => {
+  it('never returns credential or token columns to callers', async () => {
+    const email = uniqueEmail()
+    userRepo.createUser({
+      email,
+      passwordHash: await import('bcrypt').then((b) => b.hashSync('SecretPassword1!', 10)),
+      displayName: 'Safe Listing',
+      role: 'user',
+      emailVerified: 0,
+      verifyToken: 'verify-token-hash',
+      resetToken: 'reset-token-hash',
+    })
+
+    const { users, total } = userRepo.listUsers({ search: email })
+    expect(total).toBe(1)
+    const user = users[0]!
+
+    expect(user.email).toBe(email)
+    expect(user.display_name).toBe('Safe Listing')
+    expect(user.role).toBe('user')
+
+    const keys = Object.keys(user)
+    expect(keys).not.toContain('password_hash')
+    expect(keys).not.toContain('verify_token')
+    expect(keys).not.toContain('verify_expires')
+    expect(keys).not.toContain('reset_token')
+    expect(keys).not.toContain('reset_expires')
+  })
+
+  it('still returns full rows from getUserById for internal auth use', () => {
+    const email = uniqueEmail()
+    const { id } = userRepo.createUser({
+      email,
+      passwordHash: 'internal-only',
+      displayName: 'Internal',
+      emailVerified: 1,
+    })
+    expect(userRepo.getUserById(id)?.password_hash).toBe('internal-only')
+  })
+})

backend/src/repositories/userRepo.ts

@@ -11,6 +11,9 @@ export interface DbUser {
   verify_expires: number | null
   reset_token: string | null
   reset_expires: number | null
+  storage_quota_bytes: number
+  plan: string
+  token_version: number
   created_at: number
   updated_at: number
 }
@@ -23,6 +26,8 @@ export interface CreateUserData {
   emailVerified?: number
   verifyToken?: string | null
   verifyExpires?: number | null
+  storageQuotaBytes?: number
+  plan?: string
 }
 
 export interface UpdateUserData {
@@ -34,13 +39,16 @@ export interface UpdateUserData {
   verifyExpires?: number | null
   resetToken?: string | null
   resetExpires?: number | null
+  storageQuotaBytes?: number
+  plan?: string
+  tokenVersion?: number
 }
 
 export function createUser(data: CreateUserData): { id: number } {
   const db = getDb()
   const result = db.prepare(`
-    INSERT INTO users (email, password_hash, display_name, role, email_verified, verify_token, verify_expires)
-    VALUES (?, ?, ?, ?, ?, ?, ?)
+    INSERT INTO users (email, password_hash, display_name, role, email_verified, verify_token, verify_expires, storage_quota_bytes, plan)
+    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
   `).run(
     data.email.toLowerCase().trim(),
     data.passwordHash,
@@ -48,7 +56,9 @@ export function createUser(data: CreateUserData): { id: number } {
     data.role ?? 'user',
     data.emailVerified ?? 1,
     data.verifyToken ?? null,
-    data.verifyExpires ?? null
+    data.verifyExpires ?? null,
+    data.storageQuotaBytes ?? 1073741824,
+    data.plan ?? 'free'
   )
   return { id: result.lastInsertRowid as number }
 }
@@ -63,14 +73,14 @@ export function getUserById(id: number): DbUser | undefined {
   return db.prepare('SELECT * FROM users WHERE id = ?').get(id) as DbUser | undefined
 }
 
-export function getUserByVerifyToken(token: string): DbUser | undefined {
+export function getUserByVerifyTokenHash(tokenHash: string): DbUser | undefined {
   const db = getDb()
-  return db.prepare('SELECT * FROM users WHERE verify_token = ?').get(token) as DbUser | undefined
+  return db.prepare('SELECT * FROM users WHERE verify_token = ?').get(tokenHash) as DbUser | undefined
 }
 
-export function getUserByResetToken(token: string): DbUser | undefined {
+export function getUserByResetTokenHash(tokenHash: string): DbUser | undefined {
   const db = getDb()
-  return db.prepare('SELECT * FROM users WHERE reset_token = ?').get(token) as DbUser | undefined
+  return db.prepare('SELECT * FROM users WHERE reset_token = ?').get(tokenHash) as DbUser | undefined
 }
 
 export function updateUser(id: number, data: UpdateUserData): boolean {
@@ -110,6 +120,18 @@ export function updateUser(id: number, data: UpdateUserData): boolean {
     fields.push('reset_expires = ?')
     values.push(data.resetExpires)
   }
+  if (data.storageQuotaBytes !== undefined) {
+    fields.push('storage_quota_bytes = ?')
+    values.push(data.storageQuotaBytes)
+  }
+  if (data.plan !== undefined) {
+    fields.push('plan = ?')
+    values.push(data.plan)
+  }
+  if (data.tokenVersion !== undefined) {
+    fields.push('token_version = ?')
+    values.push(data.tokenVersion)
+  }
 
   if (fields.length === 0) return false
 
@@ -138,13 +160,30 @@ export function countAdmins(): number {
   return row.cnt
 }
 
-export function listUsers(options: { limit?: number; offset?: number; search?: string } = {}): { users: DbUser[]; total: number } {
+/** User row safe for API exposure — no password/token material. */
+export interface SafeUser {
+  id: number
+  email: string
+  display_name: string
+  role: 'user' | 'admin'
+  email_verified: number
+  plan: string
+  storage_quota_bytes: number
+  created_at: number
+}
+
+const SAFE_USER_COLUMNS =
+  'id, email, display_name, role, email_verified, plan, storage_quota_bytes, created_at'
+
+export function listUsers(options: { limit?: number; offset?: number; search?: string } = {}): { users: SafeUser[]; total: number } {
   const db = getDb()
   const limit = Math.min(options.limit ?? 50, 200)
   const offset = options.offset ?? 0
   const search = options.search ?? ''
 
-  let query = 'SELECT * FROM users'
+  // Explicit column list so credential/token material can never leak into
+  // API responses, even if new sensitive columns are added later.
+  let query = `SELECT ${SAFE_USER_COLUMNS} FROM users`
   let countQuery = 'SELECT COUNT(*) AS total FROM users'
   const params: unknown[] = []
   const countParams: unknown[] = []
@@ -159,13 +198,8 @@ export function listUsers(options: { limit?: number; offset?: number; search?: s
   query += ' ORDER BY created_at DESC LIMIT ? OFFSET ?'
   params.push(limit, offset)
 
-  const users = db.prepare(query).all(...params) as DbUser[]
+  const users = db.prepare(query).all(...params) as SafeUser[]
   const countRow = db.prepare(countQuery).get(...countParams) as { total: number }
 
   return { users, total: countRow.total }
 }
-
-export function promoteFirstUserToAdmin(): void {
-  const db = getDb()
-  db.prepare("UPDATE users SET role = 'admin' WHERE id = (SELECT MIN(id) FROM users)").run()
-}

backend/src/routes/admin.ts

@@ -1,4 +1,5 @@
 import { Router } from 'express'
+import { z } from 'zod'
 import { validateBody, validateQuery, validateParams } from '../middleware/validate.js'
 import { asyncHandler } from '../utils/asyncHandler.js'
 import { requireAuth, requireAdmin } from '../middleware/auth.js'
@@ -6,7 +7,8 @@ import { AppError } from '../middleware/error.js'
 import * as userRepo from '../repositories/userRepo.js'
 import * as resultRepo from '../repositories/resultRepo.js'
 import * as settingsRepo from '../repositories/settingsRepo.js'
-import { updateUserRoleSchema, updateSettingSchema, listUsersQuerySchema, userIdParamSchema } from '../validators/adminSchemas.js'
+import { updateUserRoleSchema, updateSettingSchema, updateSettingsBatchSchema, listUsersQuerySchema, userIdParamSchema } from '../validators/adminSchemas.js'
+import { gradeQuestionWithAI } from '../services/aiGrading.js'
 import type { Request } from 'express'
 
 const router = Router()
@@ -124,19 +126,44 @@ router.get(
 router.get(
   '/settings',
   asyncHandler(async (_req, res) => {
-    res.json(settingsRepo.getAllSettings())
+    res.json({ settings: settingsRepo.getAllSettings() })
   })
 )
 
 // PUT /api/admin/settings
 router.put(
   '/settings',
-  validateBody(updateSettingSchema),
+  validateBody(updateSettingsBatchSchema),
   asyncHandler(async (req: Request, res) => {
-    const { key, value } = req.body
-    settingsRepo.setSetting(key, value)
+    const { settings } = req.body
+    const entries = Object.entries(settings) as Array<[string, string]>
+    settingsRepo.setSettingsBatch(entries)
     res.json({ success: true })
   })
 )
 
+// POST /api/admin/test-ai
+router.post(
+  '/test-ai',
+  validateBody(z.object({
+    provider: z.string().min(1),
+    apiKey: z.string().min(1),
+    model: z.string().min(1),
+    baseURL: z.string().optional(),
+  })),
+  asyncHandler(async (req: Request, res) => {
+    const { provider, apiKey, model, baseURL } = req.body
+    const result = await gradeQuestionWithAI(
+      {
+        type: 'short-answer',
+        question: { prompt: 'What is 2+2?', answer: '4' },
+        answer: '4',
+        language: 'en',
+      },
+      { provider, apiKey, model, baseURL },
+    )
+    res.json(result.data)
+  }),
+)
+
 export default router

backend/src/routes/ai.ts

@@ -0,0 +1,157 @@
+import { Router } from 'express'
+import { z } from 'zod'
+import { validateBody } from '../middleware/validate.js'
+import { asyncHandler } from '../utils/asyncHandler.js'
+import { requireAuth } from '../middleware/auth.js'
+import { generateQuestions, getHint, tutorChat } from '../services/aiAssist.js'
+import { getResultById } from '../repositories/resultRepo.js'
+import { enforceDailyAiQuota, recordDailyAiUsage, getUtcDateKey } from '../utils/aiQuota.js'
+import { hintSchema } from '../validators/aiSchemas.js'
+
+const router = Router()
+router.use(requireAuth)
+
+const generateSchema = z.object({
+  topic: z.string().min(1).max(2000),
+  type: z.enum([
+    'multiple-choice',
+    'multiple-select',
+    'short-answer',
+    'translation',
+    'math-input',
+    'essay',
+    'match',
+    'order',
+    'fill-in-the-blanks',
+    'true-false',
+    'code-submission',
+    'dropdown-completion',
+    'numeric-range',
+    'dictation',
+    'grammar-correction',
+    'flashcard',
+  ]),
+  count: z.number().int().min(1).max(10),
+  language: z.string().min(1).max(20),
+  context: z.string().max(8000).optional(),
+})
+
+router.post(
+  '/generate-question',
+  validateBody(generateSchema),
+  asyncHandler(async (req, res) => {
+    const body = req.body as z.infer<typeof generateSchema>
+    const userId = req.user!.userId
+    enforceDailyAiQuota(userId)
+    const result = await generateQuestions(body)
+    recordDailyAiUsage(userId, getUtcDateKey(), result.usageTokens)
+    res.json({ questions: result.data })
+  }),
+)
+
+router.post(
+  '/hint',
+  validateBody(hintSchema),
+  asyncHandler(async (req, res) => {
+    const body = req.body
+    const userId = req.user!.userId
+    enforceDailyAiQuota(userId)
+    const result = await getHint({ question: body.question, language: body.language })
+    recordDailyAiUsage(userId, getUtcDateKey(), result.usageTokens)
+    res.json(result.data)
+  }),
+)
+
+const tutorSchema = z.object({
+  resultId: z.number().int().positive(),
+  messages: z
+    .array(
+      z.object({
+        role: z.enum(['user', 'assistant']),
+        content: z.string().min(1).max(4000),
+      }),
+    )
+    .min(1)
+    .max(40),
+  language: z.string().min(1).max(20),
+})
+
+interface TokenBucket {
+  tokens: number
+  lastRefill: number
+}
+const TUTOR_RATE_LIMIT = 30
+const TUTOR_REFILL_MS = 60 * 60 * 1000
+const tutorBuckets = new Map<number, TokenBucket>()
+
+function consumeTutorToken(userId: number): boolean {
+  const now = Date.now()
+  const bucket = tutorBuckets.get(userId) ?? { tokens: TUTOR_RATE_LIMIT, lastRefill: now }
+  const elapsed = now - bucket.lastRefill
+  if (elapsed >= TUTOR_REFILL_MS) {
+    bucket.tokens = TUTOR_RATE_LIMIT
+    bucket.lastRefill = now
+  }
+  if (bucket.tokens <= 0) {
+    tutorBuckets.set(userId, bucket)
+    return false
+  }
+  bucket.tokens -= 1
+  tutorBuckets.set(userId, bucket)
+  return true
+}
+
+router.post(
+  '/tutor-chat',
+  validateBody(tutorSchema),
+  asyncHandler(async (req, res) => {
+    const body = req.body as z.infer<typeof tutorSchema>
+    const userId = req.user!.userId
+
+    if (!consumeTutorToken(userId)) {
+      res.status(429).json({ error: 'Tutor chat rate limit reached. Please try again later.' })
+      return
+    }
+
+    const result = getResultById(body.resultId, userId)
+    if (!result) {
+      res.status(404).json({ error: 'Result not found' })
+      return
+    }
+
+    let exam: Record<string, unknown> = {}
+    let state: Record<string, unknown> = {}
+    try {
+      exam = JSON.parse(result.exam_json)
+    } catch {
+      res.status(500).json({ error: 'Stored exam data is corrupted' })
+      return
+    }
+    try {
+      state = JSON.parse(result.state_json)
+    } catch {
+      state = {}
+    }
+
+    enforceDailyAiQuota(userId)
+
+    const reply = await tutorChat({
+      exam,
+      state,
+      scoreSummary: {
+        title: result.title,
+        scorePoints: result.score_points,
+        totalPoints: result.total_points,
+        correctCount: result.correct_count,
+        gradedCount: result.graded_count,
+      },
+      messages: body.messages,
+      language: body.language,
+    })
+    recordDailyAiUsage(userId, getUtcDateKey(), reply.usageTokens)
+
+    res.json(reply.data)
+  }),
+)
+
+export default router

backend/src/routes/auth.ts

@@ -1,16 +1,21 @@
 import { Router } from 'express'
 import rateLimit from 'express-rate-limit'
 import { validateBody } from '../middleware/validate.js'
+import { validateQuery } from '../middleware/validate.js'
 import { requireAuth } from '../middleware/auth.js'
 import { asyncHandler } from '../utils/asyncHandler.js'
 import * as authService from '../services/authService.js'
 import * as userRepo from '../repositories/userRepo.js'
+import { hashToken, verifyToken } from '../utils/tokens.js'
+import { blacklistToken } from '../utils/tokenBlacklist.js'
+import { AppError } from '../middleware/error.js'
 import {
   registerSchema,
   loginSchema,
   updateProfileSchema,
   changePasswordSchema,
   verifyEmailSchema,
+  resendVerificationSchema,
   resetPasswordSchema,
   forgotPasswordSchema,
 } from '../validators/authSchemas.js'
@@ -26,14 +31,21 @@ const authLimiter = rateLimit({
   skipSuccessfulRequests: false,
 })
 
+const resendVerificationLimiter = rateLimit({
+  windowMs: 60 * 1000,
+  max: 1,
+  message: { error: 'Please wait a minute before requesting another verification email' },
+  standardHeaders: true,
+  skipSuccessfulRequests: false,
+})
+
 // POST /api/auth/register
 router.post(
   '/register',
   authLimiter,
   validateBody(registerSchema),
   asyncHandler(async (req, res) => {
-    const isFirstUser = userRepo.countUsers() === 0
-    const result = await authService.register(req.body, isFirstUser)
+    const result = await authService.register(req.body)
     res.json(result)
   })
 )
@@ -84,13 +96,24 @@ router.post(
 // GET /api/auth/verify
 router.get(
   '/verify',
-  validateBody(verifyEmailSchema),
+  validateQuery(verifyEmailSchema),
   asyncHandler(async (req, res) => {
-    await authService.verifyEmail(req.body)
+    await authService.verifyEmail(req.query as { token: string })
     res.json({ message: 'Email verified successfully' })
   })
 )
 
+// POST /api/auth/resend-verification
+router.post(
+  '/resend-verification',
+  resendVerificationLimiter,
+  validateBody(resendVerificationSchema),
+  asyncHandler(async (req, res) => {
+    await authService.resendVerification(req.body.email)
+    res.json({ message: 'If the account exists, a new verification link has been sent' })
+  })
+)
+
 // POST /api/auth/forgot-password
 router.post(
   '/forgot-password',
@@ -113,11 +136,41 @@ router.post(
   })
 )
 
+// POST /api/auth/logout
+router.post(
+  '/logout',
+  requireAuth,
+  asyncHandler(async (req: Request, res) => {
+    const header = req.headers.authorization
+    if (header?.startsWith('Bearer ')) {
+      const token = header.slice(7)
+      const tokenHash = hashToken(token)
+      // Blacklist until the token's real expiry so it cannot be replayed even
+      // after the in-memory blacklist is reloaded from SQLite on restart
+      try {
+        const decoded = verifyToken(token)
+        const expiresAt =
+          typeof decoded.exp === 'number' && decoded.exp * 1000 > Date.now()
+            ? decoded.exp * 1000
+            : Date.now() + 60 * 1000
+        blacklistToken(tokenHash, expiresAt)
+      } catch {
+        // Token already failed verification — nothing worth blacklisting
+      }
+    }
+    res.json({ success: true })
+  })
+)
+
 // DELETE /api/auth/me
 router.delete(
   '/me',
   requireAuth,
   asyncHandler(async (req: Request, res) => {
+    const user = userRepo.getUserById(req.user!.userId)
+    if (user?.role === 'admin' && userRepo.countAdmins() <= 1) {
+      throw new AppError(400, 'Cannot delete the last admin account')
+    }
     authService.deleteUserAccount(req.user!.userId)
     res.json({ success: true })
   })

backend/src/routes/collections.ts

@@ -0,0 +1,97 @@
+import { Router } from 'express'
+import { validateBody, validateParams } from '../middleware/validate.js'
+import { asyncHandler } from '../utils/asyncHandler.js'
+import { requireAuth } from '../middleware/auth.js'
+import { AppError } from '../middleware/error.js'
+import * as collectionRepo from '../repositories/collectionRepo.js'
+import * as examRepo from '../repositories/examRepo.js'
+import {
+  createCollectionSchema,
+  updateCollectionSchema,
+  collectionIdParamSchema,
+  moveExamSchema,
+} from '../validators/collectionSchemas.js'
+import { examIdParamSchema } from '../validators/examSchemas.js'
+import type { Request } from 'express'
+
+const router = Router()
+
+router.use(requireAuth)
+
+// GET /api/collections
+router.get(
+  '/',
+  asyncHandler(async (req: Request, res) => {
+    const collections = collectionRepo.listCollectionsByUser(req.user!.userId)
+    res.json(collections)
+  })
+)
+
+// POST /api/collections
+router.post(
+  '/',
+  validateBody(createCollectionSchema),
+  asyncHandler(async (req: Request, res) => {
+    const { id } = collectionRepo.createCollection(req.user!.userId, req.body.name)
+    res.status(201).json({ id, name: req.body.name })
+  })
+)
+
+// PUT /api/collections/:id
+router.put(
+  '/:id',
+  validateParams(collectionIdParamSchema),
+  validateBody(updateCollectionSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const updated = collectionRepo.updateCollection(id, req.user!.userId, req.body.name)
+    if (!updated) {
+      throw new AppError(404, 'Collection not found')
+    }
+    res.json({ success: true })
+  })
+)
+
+// DELETE /api/collections/:id
+router.delete(
+  '/:id',
+  validateParams(collectionIdParamSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const deleted = collectionRepo.deleteCollection(id, req.user!.userId)
+    if (!deleted) {
+      throw new AppError(404, 'Collection not found')
+    }
+    res.json({ success: true })
+  })
+)
+
+// POST /api/collections/move/:examId
+router.post(
+  '/move/:examId',
+  validateParams(examIdParamSchema),
+  validateBody(moveExamSchema),
+  asyncHandler(async (req: Request, res) => {
+    const examId = Number(req.params.examId)
+    const collectionId = req.body.collectionId ?? null
+
+    // Verify exam belongs to user
+    const exam = examRepo.getExamById(examId, req.user!.userId)
+    if (!exam) {
+      throw new AppError(404, 'Exam not found')
+    }
+
+    // If collectionId provided, verify it belongs to user
+    if (collectionId !== null) {
+      const collection = collectionRepo.getCollectionById(collectionId, req.user!.userId)
+      if (!collection) {
+        throw new AppError(404, 'Collection not found')
+      }
+    }
+
+    examRepo.setExamCollection(examId, req.user!.userId, collectionId)
+    res.json({ success: true })
+  })
+)
+
+export default router

backend/src/routes/exams.ts

@@ -4,7 +4,8 @@ import { asyncHandler } from '../utils/asyncHandler.js'
 import { requireAuth } from '../middleware/auth.js'
 import { AppError } from '../middleware/error.js'
 import * as examRepo from '../repositories/examRepo.js'
-import { saveExamSchema, updateExamSchema, examIdParamSchema } from '../validators/examSchemas.js'
+import { saveExamSchema, updateExamSchema, examIdParamSchema, favoriteSchema, shareModeSchema, batchDeleteSchema } from '../validators/examSchemas.js'
+import { sanitizeExam } from '../utils/sanitizeExam.js'
 import type { Request } from 'express'
 
 const router = Router()
@@ -32,7 +33,14 @@ router.get(
       throw new AppError(404, 'Exam not found')
     }
     const parsedExam = JSON.parse(exam.exam_json)
-    res.json({ ...parsedExam, id: exam.id })
+    let tags: string[] = []
+    try {
+      tags = JSON.parse(exam.tags ?? '[]')
+      if (!Array.isArray(tags)) tags = []
+    } catch {
+      tags = []
+    }
+    res.json({ ...parsedExam, id: exam.id, tags })
   })
 )
 
@@ -41,12 +49,14 @@ router.post(
   '/',
   validateBody(saveExamSchema),
   asyncHandler(async (req: Request, res) => {
-    const exam = req.body.exam
+    const exam = sanitizeExam(req.body.exam) as typeof req.body.exam
+    const tags = Array.isArray(req.body.tags) ? req.body.tags : []
     const { id } = examRepo.createExam(
       req.user!.userId,
       exam.title,
       exam.subtitle ?? null,
-      JSON.stringify(exam)
+      JSON.stringify(exam),
+      JSON.stringify(tags)
     )
     res.status(201).json({ id, title: exam.title })
   })
@@ -59,13 +69,15 @@ router.put(
   validateBody(updateExamSchema),
   asyncHandler(async (req: Request, res) => {
     const id = Number(req.params.id)
-    const exam = req.body.exam
+    const exam = sanitizeExam(req.body.exam) as typeof req.body.exam
+    const tags = Array.isArray(req.body.tags) ? JSON.stringify(req.body.tags) : null
     const updated = examRepo.updateExam(
       id,
       req.user!.userId,
       exam.title,
       exam.subtitle ?? null,
-      JSON.stringify(exam)
+      JSON.stringify(exam),
+      tags
     )
     if (!updated) {
       throw new AppError(404, 'Exam not found')
@@ -88,4 +100,121 @@ router.delete(
   })
 )
 
+// POST /api/exams/:id/share
+router.post(
+  '/:id/share',
+  validateParams(examIdParamSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const exam = examRepo.getExamById(id, req.user!.userId)
+    if (!exam) {
+      throw new AppError(404, 'Exam not found')
+    }
+    const token = exam.share_token ?? crypto.randomUUID().replace(/-/g, '')
+    const mode = exam.share_mode ?? 'clone'
+    examRepo.setShareToken(id, req.user!.userId, token, mode)
+    res.json({ shareToken: token, mode })
+  })
+)
+
+// PUT /api/exams/:id/share-mode
+router.put(
+  '/:id/share-mode',
+  validateParams(examIdParamSchema),
+  validateBody(shareModeSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const updated = examRepo.setShareMode(id, req.user!.userId, req.body.mode)
+    if (!updated) {
+      throw new AppError(404, 'Exam not found')
+    }
+    res.json({ success: true })
+  })
+)
+
+// GET /api/exams/cloned
+router.get(
+  '/cloned',
+  asyncHandler(async (req: Request, res) => {
+    const exams = examRepo.listClonedExams(req.user!.userId)
+    res.json(exams)
+  })
+)
+
+// POST /api/exams/batch-delete
+router.post(
+  '/batch-delete',
+  validateBody(batchDeleteSchema),
+  asyncHandler(async (req: Request, res) => {
+    const ids: number[] = req.body.ids
+    let deleted = 0
+    for (const id of ids) {
+      if (examRepo.deleteExam(id, req.user!.userId)) {
+        deleted++
+      }
+    }
+    res.json({ deleted })
+  })
+)
+
+// POST /api/exams/:id/unshare
+router.post(
+  '/:id/unshare',
+  validateParams(examIdParamSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const cleared = examRepo.clearShareToken(id, req.user!.userId)
+    if (!cleared) {
+      throw new AppError(404, 'Exam not found')
+    }
+    res.json({ success: true })
+  })
+)
+
+// PATCH /api/exams/:id/favorite
+router.patch(
+  '/:id/favorite',
+  validateParams(examIdParamSchema),
+  validateBody(favoriteSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const updated = examRepo.setFavorite(id, req.user!.userId, req.body.isFavorite)
+    if (!updated) {
+      throw new AppError(404, 'Exam not found')
+    }
+    res.json({ success: true })
+  })
+)
+
+// GET /api/exams/:id/export
+router.get(
+  '/:id/export',
+  validateParams(examIdParamSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const raw = examRepo.getExamRawJson(id, req.user!.userId)
+    if (!raw) {
+      throw new AppError(404, 'Exam not found')
+    }
+    res.setHeader('Content-Type', 'application/json')
+    res.setHeader('Content-Disposition', `attachment; filename="${encodeURIComponent(raw.title)}.json"`)
+    res.send(raw.exam_json)
+  })
+)
+
+// POST /api/exams/:id/duplicate
+router.post(
+  '/:id/duplicate',
+  validateParams(examIdParamSchema),
+  asyncHandler(async (req: Request, res) => {
+    const id = Number(req.params.id)
+    const exam = examRepo.getExamById(id, req.user!.userId)
+    if (!exam) {
+      throw new AppError(404, 'Exam not found')
+    }
+    const { id: newId } = examRepo.duplicateOwnExam(req.user!.userId, exam)
+    res.status(201).json({ id: newId, title: exam.title + ' (copy)' })
+  })
+)
+
 export default router

backend/src/routes/grade.ts

@@ -0,0 +1,26 @@
+import { Router } from 'express'
+import { validateBody } from '../middleware/validate.js'
+import { asyncHandler } from '../utils/asyncHandler.js'
+import { requireAuth } from '../middleware/auth.js'
+import { gradeQuestionWithAI } from '../services/aiGrading.js'
+import { enforceDailyAiQuota, recordDailyAiUsage, getUtcDateKey } from '../utils/aiQuota.js'
+import { gradeRequestSchema, type GradeRequestBody } from '../validators/gradeSchemas.js'
+
+const router = Router()
+
+router.use(requireAuth)
+
+router.post(
+  '/',
+  validateBody(gradeRequestSchema),
+  asyncHandler(async (req, res) => {
+    const { type, question, answer, language } = req.body as GradeRequestBody
+    const userId = req.user!.userId
+    enforceDailyAiQuota(userId)
+    const result = await gradeQuestionWithAI({ type, question, answer, language })
+    recordDailyAiUsage(userId, getUtcDateKey(), result.usageTokens)
+    res.json(result.data)
+  }),
+)
+
+export default router

backend/src/routes/results.ts

@@ -4,7 +4,10 @@ import { asyncHandler } from '../utils/asyncHandler.js'
 import { requireAuth } from '../middleware/auth.js'
 import { AppError } from '../middleware/error.js'
 import * as resultRepo from '../repositories/resultRepo.js'
+import * as examRepo from '../repositories/examRepo.js'
 import { submitResultSchema, resultIdParamSchema } from '../validators/resultSchemas.js'
+import { analyzeResults } from '../services/studyCoach.js'
+import { enforceDailyAiQuota, recordDailyAiUsage, getUtcDateKey } from '../utils/aiQuota.js'
 import type { Request } from 'express'
 
 const router = Router()
@@ -78,4 +81,53 @@ router.delete(
   })
 )
 
+// GET /api/results/analyze
+router.get(
+  '/analyze',
+  asyncHandler(async (req: Request, res) => {
+    const userId = req.user!.userId
+    const rawResults = resultRepo.getResultsWithExamJson(userId, 200)
+    const lang = typeof req.query.lang === 'string' ? req.query.lang : 'en'
+    enforceDailyAiQuota(userId)
+    const analysis = await analyzeResults(rawResults, lang)
+    recordDailyAiUsage(userId, getUtcDateKey(), analysis.usageTokens)
+
+    // Find weakest exam (lowest score that still exists in workspace)
+    let weakestExamId: number | null = null
+    if (rawResults.length > 0) {
+      const sorted = [...rawResults].sort((a, b) => {
+        const pa = a.total_points > 0 ? a.score_points / a.total_points : 0
+        const pb = b.total_points > 0 ? b.score_points / b.total_points : 0
+        return pa - pb
+      })
+      for (const r of sorted) {
+        if (r.exam_id) {
+          const exam = examRepo.getExamById(r.exam_id, req.user!.userId)
+          if (exam) {
+            weakestExamId = r.exam_id
+            break
+          }
+        }
+      }
+    }
+
+    res.json({ ...analysis.data, weakestExamId })
+  })
+)
+
+// GET /api/results/trends
+router.get(
+  '/trends',
+  asyncHandler(async (req: Request, res) => {
+    const raw = resultRepo.getScoreTrends(req.user!.userId, 30)
+    const trends = raw.map((r) => ({
+      completed_at: r.completed_at,
+      score_pct: r.total_points > 0 ? Math.round((r.score_points / r.total_points) * 100) : 0,
+      title: r.title,
+      exam_id: r.exam_id,
+    }))
+    res.json(trends)
+  })
+)
+
 export default router

backend/src/routes/setup.ts

@@ -3,6 +3,7 @@ import bcrypt from 'bcrypt'
 import { validateBody } from '../middleware/validate.js'
 import { asyncHandler } from '../utils/asyncHandler.js'
 import { AppError } from '../middleware/error.js'
+import { getDb } from '../db/database.js'
 import * as userRepo from '../repositories/userRepo.js'
 import * as settingsRepo from '../repositories/settingsRepo.js'
 import { setupSchema } from '../validators/setupSchemas.js'
@@ -13,7 +14,7 @@ const router = Router()
 const SALT_ROUNDS = 10
 
 function getSiteTitle(): string | null {
-  return settingsRepo.getSetting('site_title') ?? null
+  return settingsRepo.getSetting('site_name') ?? null
 }
 
 // GET /api/setup/status
@@ -21,8 +22,11 @@ router.get(
   '/status',
   asyncHandler(async (_req, res) => {
     const title = getSiteTitle()
+    // Setup is complete once an admin account exists — not merely because
+    // default settings were seeded
+    const completed = userRepo.countAdmins() > 0
     res.json({
-      completed: !!title,
+      completed,
       siteTitle: title ?? undefined,
     })
   })
@@ -33,60 +37,68 @@ router.post(
   '/',
   validateBody(setupSchema),
   asyncHandler(async (req, res) => {
-    if (getSiteTitle()) {
-      throw new AppError(400, 'Setup already completed')
-    }
+    const db = getDb()
 
-    if (userRepo.countUsers() > 0) {
-      throw new AppError(400, 'Users already exist')
-    }
+    // Atomic transaction prevents race conditions between concurrent setup requests
+    const tx = db.transaction(() => {
+      // Gate on admins, not on users or settings: a fresh instance has default
+      // settings seeded, and an instance that lost its admin can re-bootstrap
+      if (userRepo.countAdmins() > 0) {
+        throw new AppError(400, 'Setup already completed')
+      }
 
-    const {
-      email,
-      password,
-      displayName,
-      siteTitle,
-      language,
-      smtpHost,
-      smtpPort,
-      smtpUser,
-      smtpPass,
-      smtpFrom,
-      smtpSecure,
-      appUrl,
-    } = req.body
+      const {
+        email,
+        password,
+        displayName,
+        siteTitle,
+        language,
+        smtpHost,
+        smtpPort,
+        smtpUser,
+        smtpPass,
+        smtpFrom,
+        smtpSecure,
+        appUrl,
+      } = req.body
 
-    const passwordHash = await bcrypt.hash(password, SALT_ROUNDS)
+      const passwordHash = bcrypt.hashSync(password, SALT_ROUNDS)
 
-    const { id } = userRepo.createUser({
-      email,
-      passwordHash,
-      displayName,
-      role: 'admin',
-      emailVerified: 1,
+      const { id } = userRepo.createUser({
+        email,
+        passwordHash,
+        displayName,
+        role: 'admin',
+        emailVerified: 1,
+      })
+
+      const settings: Array<[string, string]> = [
+        ['site_name', siteTitle?.trim() || 'BrainWave'],
+        ['site_language', language || 'en'],
+        ['maintenance_mode', 'false'],
+      ]
+
+      if (smtpHost !== undefined) settings.push(['smtp_host', smtpHost])
+      if (smtpPort !== undefined) settings.push(['smtp_port', smtpPort])
+      if (smtpUser !== undefined) settings.push(['smtp_user', smtpUser])
+      if (smtpPass !== undefined) settings.push(['smtp_pass', smtpPass])
+      if (smtpFrom !== undefined) settings.push(['smtp_from', smtpFrom])
+      if (smtpSecure !== undefined) settings.push(['smtp_secure', smtpSecure])
+      if (appUrl !== undefined) settings.push(['app_url', appUrl])
+
+      settingsRepo.setSettingsBatch(settings)
+
+      return { id, email, displayName }
     })
 
-    const settings: Array<[string, string]> = [
-      ['site_title', siteTitle?.trim() || 'BrainWave'],
-      ['site_language', language || 'en'],
-      ['maintenance_mode', 'false'],
-    ]
-
-    if (smtpHost !== undefined) settings.push(['smtp_host', smtpHost])
-    if (smtpPort !== undefined) settings.push(['smtp_port', smtpPort])
-    if (smtpUser !== undefined) settings.push(['smtp_user', smtpUser])
-    if (smtpPass !== undefined) settings.push(['smtp_pass', smtpPass])
-    if (smtpFrom !== undefined) settings.push(['smtp_from', smtpFrom])
-    if (smtpSecure !== undefined) settings.push(['smtp_secure', smtpSecure])
-    if (appUrl !== undefined) settings.push(['app_url', appUrl])
-
-    settingsRepo.setSettingsBatch(settings)
+    const { id, email, displayName } = tx()
 
     const token = signToken({
       userId: id,
       email,
       displayName,
       role: 'admin',
+      tv: 0,
     })
 
     res.status(201).json({

backend/src/routes/share.test.ts

@@ -0,0 +1,14 @@
+import { describe, it, expect } from 'vitest'
+import { canClone } from './share.js'
+
+describe('canClone', () => {
+  it('rejects view-only shares', () => {
+    expect(canClone('view')).toBe(false)
+  })
+
+  it('allows clone-mode shares and legacy rows without a mode', () => {
+    expect(canClone('clone')).toBe(true)
+    expect(canClone(null)).toBe(true)
+    expect(canClone(undefined)).toBe(true)
+  })
+})

backend/src/routes/share.ts

@@ -0,0 +1,54 @@
+import { Router } from 'express'
+import { asyncHandler } from '../utils/asyncHandler.js'
+import { AppError } from '../middleware/error.js'
+import { requireAuth } from '../middleware/auth.js'
+import * as examRepo from '../repositories/examRepo.js'
+import type { Request } from 'express'
+
+const router = Router()
+
+/** Server-side enforcement of the share mode: 'view' shares must not be
+ * clonable (the frontend hides the button, but that is not a control). */
+export function canClone(shareMode: string | null | undefined): boolean {
+  return shareMode !== 'view'
+}
+
+// GET /api/share/:token — public, no auth required
+router.get(
+  '/:token',
+  asyncHandler(async (req: Request, res) => {
+    const token = String(req.params.token)
+    const exam = examRepo.getExamByShareToken(token)
+    if (!exam) {
+      throw new AppError(404, 'Shared exam not found')
+    }
+    const parsed = JSON.parse(exam.exam_json)
+    res.json({
+      title: exam.title,
+      subtitle: exam.subtitle,
+      questionCount: JSON.parse(exam.exam_json).questions?.length ?? 0,
+      exam: parsed,
+      shareMode: exam.share_mode ?? 'clone',
+    })
+  })
+)
+
+// POST /api/share/:token/clone — requires auth
+router.post(
+  '/:token/clone',
+  requireAuth,
+  asyncHandler(async (req: Request, res) => {
+    const token = String(req.params.token)
+    const source = examRepo.getExamByShareToken(token)
+    if (!source) {
+      throw new AppError(404, 'Shared exam not found')
+    }
+    if (!canClone(source.share_mode)) {
+      throw new AppError(403, 'This exam is shared as view-only and cannot be saved')
+    }
+    const { id } = examRepo.cloneExam(req.user!.userId, source, token)
+    res.status(201).json({ id, title: source.title + ' (copy)' })
+  })
+)
+
+export default router

backend/src/services/aiAssist.ts

@@ -0,0 +1,340 @@
+import { z } from 'zod'
+import { getAIClient, getAIModelForTask } from './aiClient.js'
+import { AiUsageResult, estimateTokensFromMessages, estimateTokensFromText, estimateTotalTokens, resolveUsageTokens } from '../utils/aiTokens.js'
+import type { ChatCompletionMessageParam } from 'openai/resources/index.js'
+
+export type QuestionType =
+  | 'multiple-choice'
+  | 'multiple-select'
+  | 'short-answer'
+  | 'translation'
+  | 'math-input'
+  | 'essay'
+  | 'match'
+  | 'order'
+  | 'fill-in-the-blanks'
+  | 'true-false'
+  | 'code-submission'
+  | 'dropdown-completion'
+  | 'numeric-range'
+  | 'dictation'
+  | 'grammar-correction'
+  | 'flashcard'
+
+const choiceSchema = z.object({
+  id: z.string().min(1),
+  text: z.string(),
+})
+
+const matchItemSchema = z.object({
+  id: z.string().min(1),
+  text: z.string(),
+})
+
+const generatedQuestionSchema = z.object({
+  type: z.enum([
+    'multiple-choice',
+    'multiple-select',
+    'short-answer',
+    'translation',
+    'math-input',
+    'essay',
+    'match',
+    'order',
+    'fill-in-the-blanks',
+    'true-false',
+    'code-submission',
+    'dropdown-completion',
+    'numeric-range',
+    'dictation',
+    'grammar-correction',
+    'flashcard',
+  ]),
+  prompt: z.string().min(1),
+  category: z.string().optional(),
+  points: z.number().int().positive().optional(),
+  explanation: z.string().optional(),
+  answer: z.union([z.string(), z.array(z.string()), z.record(z.string())]).optional(),
+  acceptedForms: z.array(z.string()).optional(),
+  caseSensitive: z.boolean().optional(),
+  sourceLanguage: z.string().optional(),
+  targetLanguage: z.string().optional(),
+  choices: z.array(choiceSchema).optional(),
+  minWords: z.number().int().nonnegative().optional(),
+  rubric: z.array(z.string()).optional(),
+  left: z.array(matchItemSchema).optional(),
+  right: z.array(matchItemSchema).optional(),
+  items: z.array(matchItemSchema).optional(),
+  textSegments: z.array(z.string()).optional(),
+  blanks: z.array(
+    z.object({
+      id: z.string().min(1),
+      acceptedAnswers: z.array(z.string()),
+      acceptedForms: z.array(z.string()).optional(),
+      caseSensitive: z.boolean().optional(),
+      ignorePunctuation: z.boolean().optional(),
+      ignoreAccents: z.boolean().optional(),
+    }),
+  ).optional(),
+  dropdowns: z.array(
+    z.object({
+      id: z.string().min(1),
+      options: z.array(choiceSchema),
+      correctOptionId: z.string(),
+    }),
+  ).optional(),
+  codeConfig: z.object({
+    language: z.string(),
+    starterCode: z.string().optional(),
+  }).optional(),
+  numericConfig: z.object({
+    answer: z.number(),
+    tolerance: z.number(),
+    min: z.number().optional(),
+    max: z.number().optional(),
+  }).optional(),
+  textToCorrect: z.string().optional(),
+})
+
+export type GeneratedQuestion = z.infer<typeof generatedQuestionSchema>
+
+export interface GenerateQuestionsRequest {
+  topic: string
+  type: QuestionType
+  count: number
+  language: string
+  context?: string
+}
+
+function shapeHintForType(type: QuestionType): string {
+  switch (type) {
+    case 'multiple-choice':
+      return `Required fields: prompt (string), choices (array of {id, text}; ids should be short like "a","b","c","d"; provide 3-4 plausible distractors), answer (string id of the correct choice).`
+    case 'multiple-select':
+      return `Required fields: prompt (string), choices (array of {id, text}; ids should be short like "a","b","c","d"), answer (array of correct choice ids).`
+    case 'short-answer':
+      return `Required fields: prompt (string), answer (string), acceptedForms (array of acceptable alternate strings, may be empty), caseSensitive (boolean, usually false).`
+    case 'translation':
+      return `Required fields: prompt (the source text), sourceLanguage (e.g. "en"), targetLanguage (e.g. "es"), answer (the canonical translation), acceptedForms (other valid translations).`
+    case 'math-input':
+      return `Required fields: prompt (string, may include LaTeX), answer (LaTeX string), acceptedForms (array of equivalent LaTeX forms).`
+    case 'essay':
+      return `Required fields: prompt (string), minWords (integer, e.g. 100), rubric (array of 3-5 short rubric criteria strings).`
+    case 'match':
+      return `Required fields: prompt (string), left (array of {id, text} 3-5 items), right (array of {id, text} 3-5 items), answer (object mapping left.id -> right.id).`
+    case 'order':
+      return `Required fields: prompt (string), items (array of {id, text} 3-6 items in any order), answer (array of item ids in the correct order).`
+    case 'fill-in-the-blanks':
+      return `Required fields: prompt (string), textSegments (array of text strings to interleave with blanks), blanks (array of {id, acceptedAnswers} where acceptedAnswers is an array of correct strings for that blank). The number of textSegments must be blanks.length + 1.`
+    case 'true-false':
+      return `Required fields: prompt (string), answer (boolean, true or false).`
+    case 'code-submission':
+      return `Required fields: prompt (string), codeConfig ({language: string, starterCode?: string}), rubric (array of 3-5 short rubric criteria strings).`
+    case 'dropdown-completion':
+      return `Required fields: prompt (string), textSegments (array of text strings to interleave with dropdowns), dropdowns (array of {id, options: [{id, text}], correctOptionId}). The number of textSegments must be dropdowns.length + 1.`
+    case 'numeric-range':
+      return `Required fields: prompt (string), numericConfig ({answer: number, tolerance: number, min?: number, max?: number}), answer (same number as numericConfig.answer).`
+    case 'dictation':
+      return `Required fields: prompt (string), audio ({src: string, a URL to an audio file}), answer (the correct text), acceptedForms (array of acceptable alternate strings), caseSensitive (boolean, usually false).`
+    case 'grammar-correction':
+      return `Required fields: prompt (string), textToCorrect (the sentence with errors to fix), answer (the corrected sentence), acceptedForms (array of acceptable corrected forms), caseSensitive (boolean, usually false).`
+    case 'flashcard':
+      return `Required fields: prompt (the front of the card, e.g. a word or phrase), answer (the back of the card, e.g. translation or definition), explanation (optional, extra info to show after reveal).`
+  }
+}
+
+export async function generateQuestions(req: GenerateQuestionsRequest): Promise<AiUsageResult<GeneratedQuestion[]>> {
+  const client = getAIClient()
+  if (!client) {
+    throw new Error('AI is not configured. Please set provider and API key in admin settings.')
+  }
+
+  const count = Math.max(1, Math.min(10, Math.floor(req.count)))
+  const model = getAIModelForTask('question_generation')
+  const shape = shapeHintForType(req.type)
+
+  const prompt = `You are an exam author. Generate ${count} high-quality "${req.type}" exam question(s) about the following topic.
+
+Topic: ${req.topic}
+${req.context ? `\nAdditional context / source material:\n${req.context}\n` : ''}
+Write all user-facing text (prompts, choices, rubric items, explanations) in ${req.language}.
+
+${shape}
+
+Respond ONLY with a JSON object of the form:
+{ "questions": [ ... ${count} question object(s) ... ] }
+
+Each question object must have "type": "${req.type}" and the fields listed above. Do not include "id" — that will be assigned later. Do not include any text outside the JSON object.`
+
+  const promptTokens = estimateTokensFromText(prompt)
+  const estimatedTokens = estimateTotalTokens(promptTokens, 1800)
+
+  const completion = await client.chat.completions.create({
+    model,
+    messages: [{ role: 'user', content: prompt }],
+    response_format: { type: 'json_object' },
+    temperature: 0.6,
+    max_completion_tokens: 1800,
+  })
+
+  const usageTokens = resolveUsageTokens(completion.usage, estimatedTokens)
+
+  const raw = completion.choices[0]?.message?.content
+  if (!raw) {
+    throw new Error('Empty response from AI provider')
+  }
+
+  let parsed: unknown
+  try {
+    parsed = JSON.parse(raw)
+  } catch {
+    throw new Error('Invalid JSON response from AI provider')
+  }
+
+  const obj = parsed as { questions?: unknown }
+  if (!Array.isArray(obj.questions)) {
+    throw new Error('AI response did not include a "questions" array')
+  }
+
+  const validated: GeneratedQuestion[] = []
+  for (const q of obj.questions) {
+    const result = generatedQuestionSchema.safeParse(q)
+    if (result.success && result.data.type === req.type) {
+      validated.push(result.data)
+    }
+  }
+
+  if (validated.length === 0) {
+    throw new Error('AI returned no valid questions for the requested type')
+  }
+  return { data: validated, usageTokens }
+}
+
+export interface HintRequest {
+  question: Record<string, unknown>
+  language: string
+}
+
+const HINT_STRIP_KEYS = ['answer', 'acceptedForms']
+
+function stripAnswerFields(question: Record<string, unknown>): Record<string, unknown> {
+  const clone: Record<string, unknown> = {}
+  for (const [k, v] of Object.entries(question)) {
+    if (HINT_STRIP_KEYS.includes(k)) continue
+    clone[k] = v
+  }
+  return clone
+}
+
+export async function getHint(req: HintRequest): Promise<AiUsageResult<{ hint: string }>> {
+  const client = getAIClient()
+  if (!client) {
+    throw new Error('AI is not configured. Please set provider and API key in admin settings.')
+  }
+
+  const safeQuestion = stripAnswerFields(req.question)
+  const model = getAIModelForTask('hint')
+
+  const messages: ChatCompletionMessageParam[] = [
+    {
+      role: 'system',
+      content: `You are a tutor helping a student during an exam. Give exactly one short hint (1-2 sentences) in ${req.language} that nudges the student toward the right approach. Never reveal the answer, never restate the answer in different words, and never give the answer to a multiple-choice option. Focus on the concept or strategy. Respond ONLY with a JSON object: { "hint": string }.`,
+    },
+    {
+      role: 'user',
+      content: `Question:\n${JSON.stringify(safeQuestion)}`,
+    },
+  ]
+
+  const promptTokens = estimateTokensFromMessages(messages as Array<{ content: string }>)
+  const estimatedTokens = estimateTotalTokens(promptTokens, 160)
+
+  const completion = await client.chat.completions.create({
+    model,
+    messages,
+    response_format: { type: 'json_object' },
+    temperature: 0.4,
+    max_completion_tokens: 160,
+  })
+
+  const usageTokens = resolveUsageTokens(completion.usage, estimatedTokens)
+
+  const raw = completion.choices[0]?.message?.content
+  if (!raw) {
+    throw new Error('Empty response from AI provider')
+  }
+  let parsed: unknown
+  try {
+    parsed = JSON.parse(raw)
+  } catch {
+    throw new Error('Invalid JSON response from AI provider')
+  }
+  const obj = parsed as Record<string, unknown>
+  const hint = typeof obj.hint === 'string' ? obj.hint.trim() : ''
+  if (!hint) {
+    throw new Error('AI did not return a hint')
+  }
+  return { data: { hint }, usageTokens }
+}
+
+export interface TutorChatMessage {
+  role: 'user' | 'assistant'
+  content: string
+}
+
+export interface TutorChatRequest {
+  exam: Record<string, unknown>
+  state: Record<string, unknown>
+  scoreSummary: {
+    title: string
+    scorePoints: number
+    totalPoints: number
+    correctCount: number
+    gradedCount: number
+  }
+  messages: TutorChatMessage[]
+  language: string
+}
+
+export async function tutorChat(req: TutorChatRequest): Promise<AiUsageResult<{ reply: string }>> {
+  const client = getAIClient()
+  if (!client) {
+    throw new Error('AI is not configured. Please set provider and API key in admin settings.')
+  }
+
+  const model = getAIModelForTask('tutor_chat')
+  const recent = req.messages.slice(-10)
+
+  const systemPrompt = `You are a friendly, concise tutor reviewing a completed exam attempt with a student. Reply in ${req.language}. Keep answers short (under 200 words). When the student references a question by number, use the exam's question order. You may explain mistakes, give similar practice problems, or clarify rubric criteria. You may reference the student's actual answers and the AI feedback already produced. Never invent score numbers — use only what's in the exam summary.
+
+Exam summary:
+- Title: ${req.scoreSummary.title}
+- Score: ${req.scoreSummary.scorePoints}/${req.scoreSummary.totalPoints}
+- Correct: ${req.scoreSummary.correctCount}/${req.scoreSummary.gradedCount}
+
+Exam (JSON): ${JSON.stringify(req.exam).slice(0, 8000)}
+
+Student's submission state (answers, flags, etc., JSON): ${JSON.stringify(req.state).slice(0, 4000)}`
+
+  const messages: ChatCompletionMessageParam[] = [
+    { role: 'system', content: systemPrompt },
+    ...recent.map((m) => ({ role: m.role, content: m.content })),
+  ]
+  const promptTokens = estimateTokensFromMessages(messages as Array<{ content: string }>)
+  const estimatedTokens = estimateTotalTokens(promptTokens, 600)
+
+  const completion = await client.chat.completions.create({
+    model,
+    messages,
+    temperature: 0.5,
+    max_completion_tokens: 600,
+  })
+
+  const usageTokens = resolveUsageTokens(completion.usage, estimatedTokens)
+
+  const reply = completion.choices[0]?.message?.content?.trim()
+  if (!reply) {
+    throw new Error('Empty response from AI provider')
+  }
+  return { data: { reply }, usageTokens }
+}

backend/src/services/aiClient.ts

@@ -0,0 +1,45 @@
+import OpenAI from 'openai'
+import { getSetting } from '../repositories/settingsRepo.js'
+
+export interface AIClientOverride {
+  provider?: string
+  apiKey?: string
+  baseURL?: string
+}
+
+export type AiTask = 'hint' | 'question_generation' | 'grading' | 'tutor_chat' | 'study_coach'
+
+export function getAIClient(override?: AIClientOverride): OpenAI | null {
+  const provider = override?.provider ?? getSetting('ai_provider')
+  const apiKey = override?.apiKey ?? getSetting('ai_api_key')
+  if (!provider || !apiKey) return null
+
+  const customBase = override?.baseURL ?? getSetting('ai_base_url')
+  const baseURL = provider === 'openai' ? undefined : (customBase || undefined)
+  return new OpenAI({ apiKey, baseURL })
+}
+
+export function getAIModel(override?: string): string {
+  return override || getSetting('ai_model') || 'gpt-4o-mini'
+}
+
+const TASK_MODEL_KEYS: Record<AiTask, string> = {
+  hint: 'ai_model_hint',
+  question_generation: 'ai_model_generate',
+  grading: 'ai_model_grading',
+  tutor_chat: 'ai_model_tutor',
+  study_coach: 'ai_model_study_coach',
+}
+
+function normalizeModel(value: string | undefined): string | undefined {
+  const trimmed = value?.trim()
+  return trimmed ? trimmed : undefined
+}
+
+export function getAIModelForTask(task: AiTask, override?: string): string {
+  const explicit = normalizeModel(override)
+  if (explicit) return explicit
+
+  const taskModel = normalizeModel(getSetting(TASK_MODEL_KEYS[task]))
+  return taskModel || getAIModel()
+}

backend/src/services/aiGrading.ts

@@ -0,0 +1,183 @@
+import { getAIClient, getAIModelForTask } from './aiClient.js'
+import { AiUsageResult, estimateTokensFromText, estimateTotalTokens, resolveUsageTokens } from '../utils/aiTokens.js'
+
+export interface GradingResult {
+  suggestedGrade: number
+  feedback: string
+  detail?: unknown
+}
+
+interface GradeRequest {
+  type: 'essay' | 'short-answer' | 'translation' | 'math' | 'ordering' | 'match'
+  question: Record<string, unknown>
+  answer: unknown
+  language: string
+}
+
+function buildPrompt(req: GradeRequest): string {
+  const { type, question, answer, language } = req
+
+  const base = `You are an exam grading assistant. Grade the student's answer and respond ONLY with a JSON object containing:
+- "suggestedGrade": number between 0.0 and 1.0
+- "feedback": string with 1-3 sentences explaining the grade in ${language}
+- "detail": type-specific breakdown object (see below)
+
+Do not include any text outside the JSON object.`
+
+  switch (type) {
+    case 'essay': {
+      const rubric = (question.rubric as string[] | undefined) ?? []
+      return `${base}
+
+Question: ${question.prompt}
+Rubric criteria: ${rubric.join('; ') || 'None provided'}
+Student answer: ${String(answer ?? '')}
+
+Evaluate how well the essay covers the rubric criteria, structure, and quality. Provide "detail" as:
+{ "rubricBreakdown": [{ "item": string, "met": boolean }] }
+Each item should correspond to a rubric criterion.`
+    }
+
+    case 'short-answer': {
+      const accepted = [question.answer as string, ...(question.acceptedForms as string[] | undefined ?? [])].filter(Boolean)
+      return `${base}
+
+Question: ${question.prompt}
+Accepted answers: ${accepted.join(' | ')}
+Student answer: ${String(answer ?? '')}
+
+Determine if the student's answer is semantically equivalent to any accepted form. Provide "detail" as:
+{ "matchedForm": string | null, "reason": string }`
+    }
+
+    case 'translation': {
+      const accepted = [question.answer as string, ...(question.acceptedForms as string[] | undefined ?? [])].filter(Boolean)
+      const source = question.sourceLanguage as string
+      const target = question.targetLanguage as string
+      return `${base}
+
+Translate from ${source} to ${target}.
+Question: ${question.prompt}
+Accepted translations: ${accepted.join(' | ')}
+Student answer: ${String(answer ?? '')}
+
+Evaluate meaning accuracy and fluency, not literal word-for-word matching. Provide "detail" as:
+{ "accuracy": number (0-1), "fluency": number (0-1), "notes": string }`
+    }
+
+    case 'math': {
+      const accepted = [question.answer as string, ...(question.acceptedForms as string[] | undefined ?? [])].filter(Boolean)
+      return `${base}
+
+Question: ${question.prompt}
+Accepted answers (LaTeX): ${accepted.join(' | ')}
+Student answer (LaTeX): ${String(answer ?? '')}
+
+Determine if the student's LaTeX expression is mathematically equivalent to the accepted answer. Provide "detail" as:
+{ "equivalent": boolean, "explanation": string }`
+    }
+
+    case 'ordering': {
+      const correctOrder = question.answer as string[]
+      const items = question.items as Array<{ id: string; text: string }> | undefined
+      const itemMap = new Map(items?.map(i => [i.id, i.text]) ?? [])
+      const given = answer as string[]
+      const correctTexts = correctOrder.map(id => itemMap.get(id) ?? id)
+      const givenTexts = given?.map(id => itemMap.get(id) ?? id) ?? []
+      return `${base}
+
+Question: ${question.prompt}
+Correct order: ${correctTexts.join(' → ')}
+Student order: ${givenTexts.join(' → ')}
+
+Determine how many items are in the correct position. Provide "detail" as:
+{ "correctPositions": number[], "totalItems": number }
+correctPositions should be 1-based indices of items in the correct position.`
+    }
+
+    case 'match': {
+      const correctPairs = question.answer as Record<string, string>
+      const left = question.left as Array<{ id: string; text: string }> | undefined
+      const right = question.right as Array<{ id: string; text: string }> | undefined
+      const leftMap = new Map(left?.map(i => [i.id, i.text]) ?? [])
+      const rightMap = new Map(right?.map(i => [i.id, i.text]) ?? [])
+      const given = (answer as Record<string, string> | undefined) ?? {}
+      const correctPairTexts: string[] = []
+      const incorrectPairTexts: string[] = []
+      for (const [lId, rId] of Object.entries(correctPairs)) {
+        const pairText = `${leftMap.get(lId) ?? lId} → ${rightMap.get(rId) ?? rId}`
+        if (given[lId] === rId) {
+          correctPairTexts.push(pairText)
+        } else {
+          const actualR = given[lId] ? (rightMap.get(given[lId]) ?? given[lId]) : '(unanswered)'
+          incorrectPairTexts.push(`${leftMap.get(lId) ?? lId} → ${actualR} (should be ${rightMap.get(rId) ?? rId})`)
+        }
+      }
+      return `${base}
+
+Question: ${question.prompt}
+Correct pairings:
+${Object.entries(correctPairs).map(([l, r]) => `${leftMap.get(l) ?? l} → ${rightMap.get(r) ?? r}`).join('\n')}
+Student pairings:
+${Object.entries(given).map(([l, r]) => `${leftMap.get(l) ?? l} → ${rightMap.get(r) ?? r}`).join('\n')}
+
+Determine partial credit based on correct pairings. Provide "detail" as:
+{ "correctPairs": string[], "incorrectPairs": string[] }
+Use the human-readable text labels in the arrays.`
+    }
+
+    default:
+      return base
+  }
+}
+
+export async function gradeQuestionWithAI(
+  req: GradeRequest,
+  override?: { provider?: string; apiKey?: string; baseURL?: string; model?: string },
+): Promise<AiUsageResult<GradingResult>> {
+  const client = getAIClient(override)
+  if (!client) {
+    throw new Error('AI grading is not configured. Please set provider and API key in admin settings.')
+  }
+
+  const model = getAIModelForTask('grading', override?.model)
+  const prompt = buildPrompt(req)
+  const promptTokens = estimateTokensFromText(prompt)
+  const estimatedTokens = estimateTotalTokens(promptTokens, 800)
+
+  const completion = await client.chat.completions.create({
+    model,
+    messages: [{ role: 'user', content: prompt }],
+    response_format: { type: 'json_object' },
+    temperature: 0.2,
+    max_completion_tokens: 800,
+  })
+
+  const usageTokens = resolveUsageTokens(completion.usage, estimatedTokens)
+
+  const raw = completion.choices[0]?.message?.content
+  if (!raw) {
+    throw new Error('Empty response from AI provider')
+  }
+
+  let parsed: unknown
+  try {
+    parsed = JSON.parse(raw)
+  } catch {
+    throw new Error('Invalid JSON response from AI provider')
+  }
+
+  const obj = parsed as Record<string, unknown>
+  const suggestedGrade = typeof obj.suggestedGrade === 'number'
+    ? Math.max(0, Math.min(1, obj.suggestedGrade))
+    : 0
+
+  return {
+    data: {
+    suggestedGrade,
+    feedback: typeof obj.feedback === 'string' ? obj.feedback : '',
+    detail: obj.detail,
+    },
+    usageTokens,
+  }
+}

backend/src/services/authService.test.ts

@@ -0,0 +1,106 @@
+import { describe, it, expect, vi } from 'vitest'
+import bcrypt from 'bcrypt'
+
+vi.mock('../utils/email.js', async (importOriginal) => ({
+  ...(await importOriginal<object>()),
+  sendVerificationEmail: vi.fn(async () => {}),
+  sendPasswordResetEmail: vi.fn(async () => {}),
+}))
+
+import * as authService from './authService.js'
+import { sendPasswordResetEmail } from '../utils/email.js'
+import * as userRepo from '../repositories/userRepo.js'
+
+async function seedUser(overrides: Partial<userRepo.CreateUserData> = {}): Promise<number> {
+  const email = overrides.email ?? `svc-${Math.random().toString(36).slice(2)}@example.com`
+  const { id } = userRepo.createUser({
+    email,
+    passwordHash: await bcrypt.hash('OldPassword1!', 10),
+    displayName: 'Svc Test',
+    emailVerified: 1,
+    ...overrides,
+  })
+  return id
+}
+
+describe('authService.register', () => {
+  it('registers new accounts as plain users (admin bootstrap is the setup wizard)', async () => {
+    const email = `new-${Math.random().toString(36).slice(2)}@example.com`
+    const result = await authService.register({
+      email,
+      password: 'Sup3rSecure!pass',
+      displayName: 'New User',
+    })
+
+    if (!('token' in result)) throw new Error('expected an AuthResult with a token')
+    expect(result.token).toBeTruthy()
+    expect(result.user.role).toBe('user')
+
+    const dbUser = userRepo.getUserByEmail(email)
+    expect(dbUser?.role).toBe('user')
+    expect(dbUser?.email_verified).toBe(0)
+  })
+
+  it('responds to duplicate emails with a token-less success-shaped body (no enumeration oracle)', async () => {
+    const id = await seedUser()
+    const existing = userRepo.getUserById(id)!
+
+    const before = userRepo.countUsers()
+    const result = await authService.register({
+      email: existing.email.toUpperCase(),
+      password: 'Whatever!123',
+      displayName: 'Imposter',
+    })
+
+    expect('token' in result).toBe(false)
+    expect('message' in result && typeof result.message).toBe('string')
+    expect(userRepo.countUsers()).toBe(before)
+
+    // The original account must be untouched
+    const after = userRepo.getUserById(id)!
+    expect(after.display_name).toBe(existing.display_name)
+  })
+})
+
+describe('password rotation revokes sessions', () => {
+  it('changePassword bumps token_version', async () => {
+    const id = await seedUser()
+    const before = userRepo.getUserById(id)!
+
+    await authService.changePassword(id, { currentPassword: 'OldPassword1!', newPassword: 'N3wPassword!x' })
+
+    const after = userRepo.getUserById(id)!
+    expect(after.password_hash).not.toBe(before.password_hash)
+    expect(after.token_version).toBe((before.token_version ?? 0) + 1)
+  })
+
+  it('changePassword rejects a wrong current password', async () => {
+    const id = await seedUser()
+    const before = userRepo.getUserById(id)!
+
+    await expect(
+      authService.changePassword(id, { currentPassword: 'WrongPassword!', newPassword: 'N3wPassword!x' }),
+    ).rejects.toThrow()
+
+    expect(userRepo.getUserById(id)!.token_version).toBe(before.token_version)
+  })
+
+  it('resetPassword bumps token_version and clears the reset token', async () => {
+    const id = await seedUser({ emailVerified: 0 })
+    const user = userRepo.getUserById(id)!
+    const email = user.email
+
+    await authService.forgotPassword(email)
+    const calls = vi.mocked(sendPasswordResetEmail).mock.calls
+    const rawToken = calls.at(-1)?.[1] as string | undefined
+    expect(rawToken).toBeTruthy()
+
+    await authService.resetPassword({ token: rawToken!, newPassword: 'BrandNew!123' })
+    const after = userRepo.getUserById(id)!
+
+    expect(after.token_version).toBe((user.token_version ?? 0) + 1)
+    expect(after.reset_token).toBeNull()
+    expect(after.reset_expires).toBeNull()
+    expect(bcrypt.compareSync('BrandNew!123', after.password_hash)).toBe(true)
+  })
+})

backend/src/services/authService.ts

@@ -1,8 +1,9 @@
 import bcrypt from 'bcrypt'
 import * as userRepo from '../repositories/userRepo.js'
-import { signToken, generateVerificationToken } from '../utils/tokens.js'
+import { signToken, generateVerificationToken, hashToken } from '../utils/tokens.js'
 import { sendVerificationEmail, sendPasswordResetEmail } from '../utils/email.js'
 import { AppError } from '../middleware/error.js'
+import * as storageRepo from '../repositories/storageRepo.js'
 import type { RegisterInput, LoginInput, UpdateProfileInput, ChangePasswordInput, VerifyEmailInput, ResetPasswordInput } from '../validators/authSchemas.js'
 
 const SALT_ROUNDS = 10
@@ -14,38 +15,21 @@ export interface AuthResult {
   user: { id: number; email: string; displayName: string; role: string }
 }
 
-export async function register(input: RegisterInput, isFirstUser: boolean): Promise<AuthResult> {
-  const existing = userRepo.getUserByEmail(input.email)
-  if (existing) {
-    throw new AppError(400, 'Email already registered')
-  }
-
-  const passwordHash = await bcrypt.hash(input.password, SALT_ROUNDS)
-  const role = isFirstUser ? 'admin' : 'user'
-  const verifyToken = generateVerificationToken()
-  const verifyExpires = Date.now() + VERIFY_TOKEN_EXPIRY_MS
-
-  const { id } = userRepo.createUser({
-    email: input.email,
-    passwordHash,
-    displayName: input.displayName,
-    role,
-    emailVerified: 0,
-    verifyToken,
-    verifyExpires,
-  })
-
-  const user = userRepo.getUserById(id)!
-
-  // Don't await — fire and forget so registration isn't blocked by email failures
-  sendVerificationEmail(user.email, verifyToken).catch(() => {})
+/** Response for a registration attempt we did not act on (email already exists).
+ * Deliberately indistinguishable from success so the endpoint cannot be used
+ * to enumerate registered email addresses. */
+export interface RegistrationPending {
+  message: string
+}
 
+function toAuthResult(user: userRepo.DbUser): AuthResult {
   return {
     token: signToken({
       userId: user.id,
       email: user.email,
       displayName: user.display_name,
       role: user.role as 'user' | 'admin',
+      tv: user.token_version ?? 0,
     }),
     user: {
       id: user.id,
@@ -56,6 +40,38 @@ export async function register(input: RegisterInput, isFirstUser: boolean): Prom
   }
 }
 
+export async function register(input: RegisterInput): Promise<AuthResult | RegistrationPending> {
+  // Hash before the duplicate check so response timing does not reveal whether
+  // the email is already registered (user enumeration)
+  const passwordHash = await bcrypt.hash(input.password, SALT_ROUNDS)
+
+  const existing = userRepo.getUserByEmail(input.email)
+  if (existing) {
+    return { message: 'Check your inbox to finish setting up your account.' }
+  }
+
+  const rawVerifyToken = generateVerificationToken()
+  const verifyTokenHash = hashToken(rawVerifyToken)
+  const verifyExpires = Date.now() + VERIFY_TOKEN_EXPIRY_MS
+
+  const { id } = userRepo.createUser({
+    email: input.email,
+    passwordHash,
+    displayName: input.displayName,
+    role: 'user',
+    emailVerified: 0,
+    verifyToken: verifyTokenHash,
+    verifyExpires,
+  })
+
+  const user = userRepo.getUserById(id)!
+
+  // Don't await — fire and forget so registration isn't blocked by email failures
+  sendVerificationEmail(user.email, rawVerifyToken).catch(() => {})
+
+  return toAuthResult(user)
+}
+
 export async function login(input: LoginInput): Promise<AuthResult> {
   const user = userRepo.getUserByEmail(input.email)
   if (!user) {
@@ -67,20 +83,11 @@ export async function login(input: LoginInput): Promise<AuthResult> {
     throw new AppError(401, 'Invalid email or password')
   }
 
-  return {
-    token: signToken({
-      userId: user.id,
-      email: user.email,
-      displayName: user.display_name,
-      role: user.role as 'user' | 'admin',
-    }),
-    user: {
-      id: user.id,
-      email: user.email,
-      displayName: user.display_name,
-      role: user.role,
-    },
+  if (!user.email_verified) {
+    throw new AppError(403, 'Please verify your email before logging in')
   }
+
+  return toAuthResult(user)
 }
 
 export function getMe(userId: number) {
@@ -88,12 +95,20 @@ export function getMe(userId: number) {
   if (!user) {
     throw new AppError(404, 'User not found')
   }
+  const usage = storageRepo.getUserStorageUsage(userId)
+  const usedPercent = user.storage_quota_bytes > 0
+    ? Math.round((usage.usedBytes / user.storage_quota_bytes) * 100)
+    : 0
   return {
     id: user.id,
     email: user.email,
     displayName: user.display_name,
     role: user.role,
     emailVerified: !!user.email_verified,
+    storageQuotaBytes: user.storage_quota_bytes,
+    usedBytes: usage.usedBytes,
+    usedPercent,
+    plan: user.plan,
   }
 }
 
@@ -114,11 +129,16 @@ export async function changePassword(userId: number, input: ChangePasswordInput)
   }
 
   const passwordHash = await bcrypt.hash(input.newPassword, SALT_ROUNDS)
-  userRepo.updateUser(userId, { passwordHash })
+  // Bump token version so tokens issued before the change stop working
+  userRepo.updateUser(userId, {
+    passwordHash,
+    tokenVersion: (user.token_version ?? 0) + 1,
+  })
 }
 
 export async function verifyEmail(input: VerifyEmailInput) {
-  const user = userRepo.getUserByVerifyToken(input.token)
+  const tokenHash = hashToken(input.token)
+  const user = userRepo.getUserByVerifyTokenHash(tokenHash)
   if (!user || !user.verify_expires || Date.now() > user.verify_expires) {
     throw new AppError(400, 'Invalid or expired verification token')
   }
@@ -130,6 +150,24 @@ export async function verifyEmail(input: VerifyEmailInput) {
   })
 }
 
+export async function resendVerification(email: string) {
+  const user = userRepo.getUserByEmail(email)
+  if (!user || user.email_verified) {
+    return
+  }
+
+  const rawVerifyToken = generateVerificationToken()
+  const verifyTokenHash = hashToken(rawVerifyToken)
+  const verifyExpires = Date.now() + VERIFY_TOKEN_EXPIRY_MS
+
+  userRepo.updateUser(user.id, {
+    verifyToken: verifyTokenHash,
+    verifyExpires,
+  })
+
+  sendVerificationEmail(user.email, rawVerifyToken).catch(() => {})
+}
+
 export async function forgotPassword(email?: string) {
   if (!email) {
     throw new AppError(400, 'Email is required')
@@ -141,26 +179,30 @@ export async function forgotPassword(email?: string) {
     return
   }
 
-  const resetToken = generateVerificationToken()
+  const rawResetToken = generateVerificationToken()
+  const resetTokenHash = hashToken(rawResetToken)
   const resetExpires = Date.now() + RESET_TOKEN_EXPIRY_MS
 
-  userRepo.updateUser(user.id, { resetToken, resetExpires })
+  userRepo.updateUser(user.id, { resetToken: resetTokenHash, resetExpires })
 
   // Fire and forget
-  sendPasswordResetEmail(user.email, resetToken).catch(() => {})
+  sendPasswordResetEmail(user.email, rawResetToken).catch(() => {})
 }
 
 export async function resetPassword(input: ResetPasswordInput) {
-  const user = userRepo.getUserByResetToken(input.token)
+  const tokenHash = hashToken(input.token)
+  const user = userRepo.getUserByResetTokenHash(tokenHash)
   if (!user || !user.reset_expires || Date.now() > user.reset_expires) {
     throw new AppError(400, 'Invalid or expired reset token')
   }
 
   const passwordHash = await bcrypt.hash(input.newPassword, SALT_ROUNDS)
+  // Bump token version so tokens from before the reset stop working
   userRepo.updateUser(user.id, {
     passwordHash,
     resetToken: null,
     resetExpires: null,
+    tokenVersion: (user.token_version ?? 0) + 1,
   })
 }
 

backend/src/services/studyCoach.ts

@@ -0,0 +1,162 @@
+import { getAIClient, getAIModelForTask } from './aiClient.js'
+import { AiUsageResult, estimateTokensFromText, estimateTotalTokens, resolveUsageTokens } from '../utils/aiTokens.js'
+
+export interface WeakArea {
+  category: string
+  avgScore: number
+  attempts: number
+}
+
+export interface StudyCoachResult {
+  weakAreas: WeakArea[]
+  studyTips: string[]
+  streakDays: number
+}
+
+interface ResultSummary {
+  title: string
+  scorePoints: number
+  totalPoints: number
+  correctCount: number
+  gradedCount: number
+  completedAt: number
+  categories: Record<string, { score: number; total: number }>
+}
+
+
+function calculateStreak(results: Array<{ completed_at: number }>): number {
+  if (results.length === 0) return 0
+  const days = new Set<string>()
+  for (const r of results) {
+    const d = new Date(r.completed_at * 1000)
+    days.add(`${d.getFullYear()}-${d.getMonth()}-${d.getDate()}`)
+  }
+  const sorted = Array.from(days).sort()
+  if (sorted.length === 0) return 0
+
+  const today = new Date()
+  const todayStr = `${today.getFullYear()}-${today.getMonth()}-${today.getDate()}`
+
+  let streak = 0
+  for (let i = sorted.length - 1; i >= 0; i--) {
+    const expected = new Date(today)
+    expected.setDate(today.getDate() - (sorted.length - 1 - i))
+    const expectedStr = `${expected.getFullYear()}-${expected.getMonth()}-${expected.getDate()}`
+    if (sorted[i] === expectedStr || (i === sorted.length - 1 && sorted[i] === todayStr)) {
+      streak++
+    } else if (i === sorted.length - 1) {
+      // Most recent is not today — check if it was yesterday
+      const yesterday = new Date(today)
+      yesterday.setDate(today.getDate() - 1)
+      const yestStr = `${yesterday.getFullYear()}-${yesterday.getMonth()}-${yesterday.getDate()}`
+      if (sorted[i] === yestStr) {
+        streak++
+      } else {
+        break
+      }
+    } else {
+      break
+    }
+  }
+  return streak
+}
+
+export async function analyzeResults(
+  results: Array<{
+    title: string
+    score_points: number
+    total_points: number
+    correct_count: number
+    graded_count: number
+    completed_at: number
+    exam_json: string
+  }>,
+  language = 'en',
+  options?: { allowAi?: boolean },
+): Promise<AiUsageResult<StudyCoachResult>> {
+  const streakDays = calculateStreak(results)
+
+  // Build per-category stats from exam_json
+  const categoryStats: Record<string, { score: number; total: number; attempts: number }> = {}
+  for (const r of results) {
+    let exam: { questions?: Array<{ category?: string; points?: number }> } | undefined
+    try {
+      exam = JSON.parse(r.exam_json)
+    } catch {
+      continue
+    }
+    const questions = exam?.questions ?? []
+    // We don't have per-question results in the stored result, so we approximate
+    // using the overall score distributed across categories proportionally
+    const totalQuestionPoints = questions.reduce((sum, q) => sum + (q.points ?? 1), 0)
+    if (totalQuestionPoints === 0) continue
+    const overallRatio = r.total_points > 0 ? r.score_points / r.total_points : 0
+    for (const q of questions) {
+      const cat = q.category ?? 'Uncategorized'
+      const pts = q.points ?? 1
+      if (!categoryStats[cat]) {
+        categoryStats[cat] = { score: 0, total: 0, attempts: 0 }
+      }
+      categoryStats[cat].score += pts * overallRatio
+      categoryStats[cat].total += pts
+    }
+    // Mark attempt for each unique category in this exam
+    const catsInExam = new Set(questions.map((q) => q.category ?? 'Uncategorized'))
+    for (const cat of catsInExam) {
+      categoryStats[cat].attempts++
+    }
+  }
+
+  const weakAreas: WeakArea[] = Object.entries(categoryStats)
+    .map(([category, stats]) => ({
+      category,
+      avgScore: stats.total > 0 ? Math.round((stats.score / stats.total) * 100) : 0,
+      attempts: stats.attempts,
+    }))
+    .filter((w) => w.attempts >= 1)
+    .sort((a, b) => a.avgScore - b.avgScore)
+    .slice(0, 5)
+
+  const client = getAIClient()
+  if (!client || weakAreas.length === 0 || options?.allowAi === false) {
+    return { data: { weakAreas, studyTips: [], streakDays }, usageTokens: 0 }
+  }
+
+  const model = getAIModelForTask('study_coach')
+  const prompt = `You are a study coach. A student has taken several practice exams. Based on their performance per category, suggest 2-3 concise study tips to help them improve in their weakest areas. Respond ONLY with a JSON object containing:
+- "studyTips": string[] (2-3 short tips in ${language})
+
+Do not include any text outside the JSON object.
+
+Weak areas (score %, attempts):
+${weakAreas.map((w) => `- ${w.category}: ${w.avgScore}% over ${w.attempts} attempt(s)`).join('\n')}`
+
+  const promptTokens = estimateTokensFromText(prompt)
+  const estimatedTokens = estimateTotalTokens(promptTokens, 400)
+
+  try {
+    const completion = await client.chat.completions.create({
+      model,
+      messages: [{ role: 'user', content: prompt }],
+      response_format: { type: 'json_object' },
+      temperature: 0.4,
+      max_completion_tokens: 400,
+    })
+
+    const usageTokens = resolveUsageTokens(completion.usage, estimatedTokens)
+
+    const raw = completion.choices[0]?.message?.content
+    if (!raw) {
+      return { data: { weakAreas, studyTips: [], streakDays }, usageTokens: 0 }
+    }
+
+    const parsed = JSON.parse(raw) as Record<string, unknown>
+    const tips = Array.isArray(parsed.studyTips)
+      ? parsed.studyTips.filter((t): t is string => typeof t === 'string')
+      : []
+
+    return { data: { weakAreas, studyTips: tips, streakDays }, usageTokens }
+  } catch {
+    return { data: { weakAreas, studyTips: [], streakDays }, usageTokens: 0 }
+  }
+}

backend/src/utils/aiQuota.test.ts

@@ -0,0 +1,54 @@
+import { describe, it, expect } from 'vitest'
+import * as settingsRepo from '../repositories/settingsRepo.js'
+import * as aiUsageRepo from '../repositories/aiUsageRepo.js'
+import * as userRepo from '../repositories/userRepo.js'
+import { enforceDailyAiQuota, getDailyTokenLimit, getUtcDateKey } from './aiQuota.js'
+import { AppError } from '../middleware/error.js'
+
+function seedUser(): number {
+  const email = `quota-${Math.random().toString(36).slice(2)}@example.com`
+  return userRepo.createUser({
+    email,
+    passwordHash: 'x',
+    displayName: 'Quota Test',
+    emailVerified: 1,
+  }).id
+}
+
+describe('daily AI token quota', () => {
+  it('allows everything when no limit is configured', () => {
+    settingsRepo.setSetting('ai_daily_token_limit', '0')
+    expect(getDailyTokenLimit()).toBeNull()
+    expect(() => enforceDailyAiQuota(seedUser())).not.toThrow()
+  })
+
+  it('blocks with a 429 once used tokens reach the configured limit', () => {
+    settingsRepo.setSetting('ai_daily_token_limit', '1000')
+    const userId = seedUser()
+    aiUsageRepo.incrementDailyUsage(userId, getUtcDateKey(), 1000, 1)
+
+    expect(() => enforceDailyAiQuota(userId)).toThrowError(AppError)
+    try {
+      enforceDailyAiQuota(userId)
+    } catch (err) {
+      expect(err).toBeInstanceOf(AppError)
+      expect((err as AppError).statusCode).toBe(429)
+    }
+  })
+
+  it('allows users under the limit and isolates users from each other', () => {
+    settingsRepo.setSetting('ai_daily_token_limit', '1000')
+    const heavy = seedUser()
+    const fresh = seedUser()
+    aiUsageRepo.incrementDailyUsage(heavy, getUtcDateKey(), 999, 1)
+    expect(() => enforceDailyAiQuota(heavy)).not.toThrow()
+    expect(() => enforceDailyAiQuota(fresh)).not.toThrow()
+  })
+
+  it('only counts today’s usage', () => {
+    settingsRepo.setSetting('ai_daily_token_limit', '1000')
+    const userId = seedUser()
+    aiUsageRepo.incrementDailyUsage(userId, '2000-01-01', 999_999, 1)
+    expect(() => enforceDailyAiQuota(userId)).not.toThrow()
+  })
+})

backend/src/utils/aiQuota.ts

@@ -0,0 +1,51 @@
+import { getSetting } from '../repositories/settingsRepo.js'
+import { getDailyUsage, incrementDailyUsage } from '../repositories/aiUsageRepo.js'
+import { AppError } from '../middleware/error.js'
+
+export interface AiQuotaStatus {
+  allowed: boolean
+  limit: number | null
+  usedTokens: number
+  periodDate: string
+}
+
+export function getUtcDateKey(date = new Date()): string {
+  return date.toISOString().slice(0, 10)
+}
+
+export function getDailyTokenLimit(): number | null {
+  const raw = getSetting('ai_daily_token_limit') ?? ''
+  const parsed = Number(raw)
+  if (!Number.isFinite(parsed) || parsed <= 0) return null
+  return Math.floor(parsed)
+}
+
+export function checkDailyAiQuota(userId: number): AiQuotaStatus {
+  const periodDate = getUtcDateKey()
+  const limit = getDailyTokenLimit()
+  if (!limit) {
+    return { allowed: true, limit: null, usedTokens: 0, periodDate }
+  }
+
+  const usage = getDailyUsage(userId, periodDate)
+  return {
+    allowed: usage.tokensUsed < limit,
+    limit,
+    usedTokens: usage.tokensUsed,
+    periodDate,
+  }
+}
+
+export function recordDailyAiUsage(userId: number, periodDate: string, tokens: number): void {
+  incrementDailyUsage(userId, periodDate, tokens, 1)
+}
+
+/**
+ * Throws a 429 when the user has exhausted the admin-configured daily token
+ * limit. Call before every AI provider invocation; pair with recordDailyAiUsage.
+ */
+export function enforceDailyAiQuota(userId: number): void {
+  if (!checkDailyAiQuota(userId).allowed) {
+    throw new AppError(429, 'Daily AI usage limit reached. Please try again tomorrow.')
+  }
+}

backend/src/utils/aiTokens.ts

@@ -0,0 +1,29 @@
+export interface AiUsageResult<T> {
+  data: T
+  usageTokens: number
+}
+
+export function estimateTokensFromText(text: string): number {
+  if (!text) return 0
+  return Math.max(1, Math.ceil(text.length / 4))
+}
+
+export function estimateTokensFromMessages(messages: Array<{ content: string }>): number {
+  return messages.reduce((sum, msg) => sum + estimateTokensFromText(msg.content), 0)
+}
+
+// Conservative estimate when providers omit usage details.
+export function estimateTotalTokens(promptTokens: number, maxCompletionTokens: number): number {
+  const completionEstimate = Math.max(0, Math.round(maxCompletionTokens * 0.6))
+  return Math.max(1, promptTokens + completionEstimate)
+}
+
+export function resolveUsageTokens(
+  usage: { total_tokens?: number } | undefined,
+  estimate: number,
+): number {
+  if (usage && typeof usage.total_tokens === 'number' && Number.isFinite(usage.total_tokens)) {
+    return Math.max(0, Math.round(usage.total_tokens))
+  }
+  return estimate
+}

backend/src/utils/sanitizeExam.ts

@@ -0,0 +1,30 @@
+/**
+ * Server-side sanitization for user-provided exam content.
+ * Removes script tags and event handlers from string fields.
+ */
+
+function sanitizeString(value: unknown): unknown {
+  if (typeof value !== 'string') return value
+  return value
+    .replace(/<script[^>]*>[\s\S]*?<\/script>/gi, '')
+    .replace(/<script[^>]*\/>/gi, '')
+    .replace(/javascript:/gi, '')
+    .replace(/on\w+\s*=/gi, '')
+}
+
+function sanitizeObject(obj: unknown): unknown {
+  if (typeof obj === 'string') return sanitizeString(obj)
+  if (Array.isArray(obj)) return obj.map(sanitizeObject)
+  if (obj && typeof obj === 'object') {
+    const result: Record<string, unknown> = {}
+    for (const [key, val] of Object.entries(obj)) {
+      result[key] = sanitizeObject(val)
+    }
+    return result
+  }
+  return obj
+}
+
+export function sanitizeExam(exam: Record<string, unknown>): Record<string, unknown> {
+  return sanitizeObject(exam) as Record<string, unknown>
+}

backend/src/utils/tokenBlacklist.ts

@@ -0,0 +1,47 @@
+/**
+ * In-memory token blacklist with SQLite persistence.
+ * Tokens are blacklisted on logout and expire automatically based on JWT expiry.
+ */
+
+import { getDb } from '../db/database.js'
+
+const memoryCache = new Set<string>()
+let initialized = false
+
+function initCache(): void {
+  if (initialized) return
+  const db = getDb()
+  db.exec(`
+    CREATE TABLE IF NOT EXISTS token_blacklist (
+      token_hash TEXT PRIMARY KEY,
+      expires_at INTEGER NOT NULL
+    );
+    CREATE INDEX IF NOT EXISTS idx_token_blacklist_expires ON token_blacklist(expires_at);
+  `)
+  // Purge rows that can never matter again, then load the rest into memory
+  db.prepare('DELETE FROM token_blacklist WHERE expires_at <= ?').run(Date.now())
+  const rows = db.prepare('SELECT token_hash FROM token_blacklist WHERE expires_at > ?')
+    .all(Date.now()) as { token_hash: string }[]
+  for (const row of rows) {
+    memoryCache.add(row.token_hash)
+  }
+  initialized = true
+}
+
+export function isTokenBlacklisted(tokenHash: string): boolean {
+  initCache()
+  return memoryCache.has(tokenHash)
+}
+
+export function blacklistToken(tokenHash: string, expiresAt: number): void {
+  initCache()
+  memoryCache.add(tokenHash)
+  const db = getDb()
+  db.prepare('INSERT OR IGNORE INTO token_blacklist (token_hash, expires_at) VALUES (?, ?)')
+    .run(tokenHash, expiresAt)
+}
+
+export function cleanupExpiredTokens(): void {
+  const db = getDb()
+  db.prepare('DELETE FROM token_blacklist WHERE expires_at <= ?').run(Date.now())
+}

backend/src/utils/tokens.test.ts

@@ -4,13 +4,14 @@ describe('tokens', () => {
   it('round-trips JWT payload', async () => {
     process.env.JWT_SECRET = 'test-secret-for-unit-tests-only'
     const { signToken, verifyToken } = await import('./tokens')
-    const payload = { userId: 1, email: 'a@b.com', displayName: 'Test', role: 'user' as const }
+    const payload = { userId: 1, email: 'a@b.com', displayName: 'Test', role: 'user' as const, tv: 3 }
     const token = signToken(payload)
     const decoded = verifyToken(token)
     expect(decoded.userId).toBe(1)
     expect(decoded.email).toBe('a@b.com')
     expect(decoded.displayName).toBe('Test')
     expect(decoded.role).toBe('user')
+    expect(decoded.tv).toBe(3)
   })
 
   it('throws on invalid token', async () => {
@@ -22,7 +23,7 @@ describe('tokens', () => {
   it('throws on tampered token', async () => {
     process.env.JWT_SECRET = 'test-secret-for-unit-tests-only'
     const { signToken, verifyToken } = await import('./tokens')
-    const payload = { userId: 1, email: 'a@b.com', displayName: 'Test', role: 'user' as const }
+    const payload = { userId: 1, email: 'a@b.com', displayName: 'Test', role: 'user' as const, tv: 0 }
     const token = signToken(payload)
     const tampered = token.slice(0, -5) + 'xxxxx'
     expect(() => verifyToken(tampered)).toThrow()

backend/src/utils/tokens.ts

@@ -7,16 +7,25 @@ export interface JwtPayload {
   email: string
   displayName: string
   role: 'user' | 'admin'
+  /** Token version — must match the user's current token_version or the token is rejected */
+  tv: number
 }
 
 export function signToken(payload: JwtPayload): string {
-  return jwt.sign(payload, config.jwtSecret, { expiresIn: '24h' })
+  return jwt.sign(payload, config.jwtSecret, { expiresIn: config.jwtExpiresIn } as jwt.SignOptions)
 }
 
-export function verifyToken(token: string): JwtPayload {
-  return jwt.verify(token, config.jwtSecret) as JwtPayload
+/** Verified JWT body: our claims plus the registered exp/iat timestamps. */
+export type VerifiedToken = JwtPayload & { exp?: number; iat?: number }
+
+export function verifyToken(token: string): VerifiedToken {
+  return jwt.verify(token, config.jwtSecret) as VerifiedToken
 }
 
 export function generateVerificationToken(): string {
   return crypto.randomBytes(32).toString('hex')
 }
+
+export function hashToken(token: string): string {
+  return crypto.createHash('sha256').update(token).digest('hex')
+}

backend/src/validators/adminSchemas.test.ts

@@ -1,12 +1,17 @@
 import { describe, it, expect } from 'vitest'
-import { updateUserRoleSchema, updateSettingSchema, listUsersQuerySchema, userIdParamSchema } from './adminSchemas'
+import { updateUserRoleSchema, updateSettingSchema, updateSettingsBatchSchema, listUsersQuerySchema, userIdParamSchema } from './adminSchemas'
 
 describe('updateUserRoleSchema', () => {
-  it('accepts valid role change', () => {
+  it('accepts valid role change to admin', () => {
     const result = updateUserRoleSchema.safeParse({ user_id: 1, role: 'admin' })
     expect(result.success).toBe(true)
   })
 
+  it('accepts valid role change to user', () => {
+    const result = updateUserRoleSchema.safeParse({ user_id: 5, role: 'user' })
+    expect(result.success).toBe(true)
+  })
+
   it('rejects invalid role', () => {
     const result = updateUserRoleSchema.safeParse({ user_id: 1, role: 'superadmin' })
     expect(result.success).toBe(false)
@@ -16,33 +21,104 @@ describe('updateUserRoleSchema', () => {
     const result = updateUserRoleSchema.safeParse({ user_id: 0, role: 'admin' })
     expect(result.success).toBe(false)
   })
+
+  it('rejects negative user_id', () => {
+    const result = updateUserRoleSchema.safeParse({ user_id: -1, role: 'admin' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects non-numeric user_id', () => {
+    const result = updateUserRoleSchema.safeParse({ user_id: '1', role: 'admin' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects missing fields', () => {
+    expect(updateUserRoleSchema.safeParse({ user_id: 1 }).success).toBe(false)
+    expect(updateUserRoleSchema.safeParse({ role: 'admin' }).success).toBe(false)
+  })
 })
 
 describe('updateSettingSchema', () => {
   it('accepts valid setting', () => {
-    const result = updateSettingSchema.safeParse({ key: 'app_name', value: 'BrainWave' })
+    const result = updateSettingSchema.safeParse({ key: 'site_name', value: 'BrainWave' })
     expect(result.success).toBe(true)
   })
 
+  it('rejects unknown key', () => {
+    const result = updateSettingSchema.safeParse({ key: 'unknown_key', value: 'x' })
+    expect(result.success).toBe(false)
+  })
+
   it('rejects empty key', () => {
     const result = updateSettingSchema.safeParse({ key: '', value: 'BrainWave' })
     expect(result.success).toBe(false)
   })
 
-  it('rejects empty value', () => {
-    const result = updateSettingSchema.safeParse({ key: 'app_name', value: '' })
+  it('accepts empty value (clearing a setting)', () => {
+    const result = updateSettingSchema.safeParse({ key: 'smtp_pass', value: '' })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects non-string value', () => {
+    const result = updateSettingSchema.safeParse({ key: 'site_name', value: 123 })
+    expect(result.success).toBe(false)
+  })
+
+  it('accepts each allowed key', () => {
+    const keys = [
+      'site_name', 'site_language', 'maintenance_mode', 'maintenance_message',
+      'allow_guest_mode', 'registration_enabled', 'default_theme',
+      'smtp_host', 'smtp_port', 'smtp_user', 'smtp_pass', 'smtp_from', 'smtp_secure',
+      'app_url', 'max_upload_mb', 'ai_provider', 'ai_model', 'ai_api_key', 'ai_base_url',
+    ]
+    for (const key of keys) {
+      const result = updateSettingSchema.safeParse({ key, value: 'x' })
+      expect(result.success, `key ${key} should be accepted`).toBe(true)
+    }
+  })
+})
+
+describe('updateSettingsBatchSchema', () => {
+  it('accepts valid batch', () => {
+    const result = updateSettingsBatchSchema.safeParse({
+      settings: { site_name: 'BrainWave', maintenance_mode: 'false' },
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts empty settings record', () => {
+    const result = updateSettingsBatchSchema.safeParse({ settings: {} })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts empty value in batch (clearing)', () => {
+    const result = updateSettingsBatchSchema.safeParse({
+      settings: { smtp_pass: '' },
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects non-string value in batch', () => {
+    const result = updateSettingsBatchSchema.safeParse({
+      settings: { site_name: 42 },
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects missing settings property', () => {
+    const result = updateSettingsBatchSchema.safeParse({})
     expect(result.success).toBe(false)
   })
 })
 
 describe('listUsersQuerySchema', () => {
-  it('accepts empty query', () => {
+  it('accepts empty query and defaults page to 1', () => {
     const result = listUsersQuerySchema.safeParse({})
     expect(result.success).toBe(true)
     expect((result as any).data.page).toBe(1)
   })
 
-  it('accepts page string', () => {
+  it('parses page string into number', () => {
     const result = listUsersQuerySchema.safeParse({ page: '3' })
     expect(result.success).toBe(true)
     expect((result as any).data.page).toBe(3)
@@ -53,9 +129,26 @@ describe('listUsersQuerySchema', () => {
     expect(result.success).toBe(false)
   })
 
+  it('rejects negative page', () => {
+    const result = listUsersQuerySchema.safeParse({ page: '-1' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects decimal page', () => {
+    const result = listUsersQuerySchema.safeParse({ page: '1.5' })
+    expect(result.success).toBe(false)
+  })
+
   it('accepts search', () => {
     const result = listUsersQuerySchema.safeParse({ search: 'john' })
     expect(result.success).toBe(true)
+    expect((result as any).data.search).toBe('john')
+  })
+
+  it('accepts both page and search', () => {
+    const result = listUsersQuerySchema.safeParse({ page: '2', search: 'jane' })
+    expect(result.success).toBe(true)
+    expect((result as any).data).toEqual({ page: 2, search: 'jane' })
   })
 })
 
@@ -65,8 +158,24 @@ describe('userIdParamSchema', () => {
     expect(result.success).toBe(true)
   })
 
+  it('accepts multi-digit id', () => {
+    const result = userIdParamSchema.safeParse({ id: '12345' })
+    expect(result.success).toBe(true)
+  })
+
   it('rejects non-numeric id', () => {
     const result = userIdParamSchema.safeParse({ id: 'seven' })
     expect(result.success).toBe(false)
   })
+
+  it('rejects empty id', () => {
+    const result = userIdParamSchema.safeParse({ id: '' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects id with non-digit characters', () => {
+    expect(userIdParamSchema.safeParse({ id: '1a' }).success).toBe(false)
+    expect(userIdParamSchema.safeParse({ id: '-1' }).success).toBe(false)
+    expect(userIdParamSchema.safeParse({ id: '1.0' }).success).toBe(false)
+  })
 })

backend/src/validators/adminSchemas.ts

@@ -5,9 +5,35 @@ export const updateUserRoleSchema = z.object({
   role: z.enum(['user', 'admin']),
 })
 
+const ALLOWED_SETTING_KEYS = [
+  'site_name',
+  'site_language',
+  'maintenance_mode',
+  'maintenance_message',
+  'allow_guest_mode',
+  'registration_enabled',
+  'default_theme',
+  'smtp_host',
+  'smtp_port',
+  'smtp_user',
+  'smtp_pass',
+  'smtp_from',
+  'smtp_secure',
+  'app_url',
+  'max_upload_mb',
+  'ai_provider',
+  'ai_model',
+  'ai_api_key',
+  'ai_base_url',
+] as const
+
 export const updateSettingSchema = z.object({
-  key: z.string().min(1),
-  value: z.string().min(1),
+  key: z.enum(ALLOWED_SETTING_KEYS),
+  value: z.string(),
+})
+
+export const updateSettingsBatchSchema = z.object({
+  settings: z.record(z.string()),
 })
 
 export const listUsersQuerySchema = z.object({

backend/src/validators/aiSchemas.test.ts

@@ -0,0 +1,23 @@
+import { describe, it, expect } from 'vitest'
+import { hintSchema, MAX_HINT_QUESTION_CHARS } from './aiSchemas.js'
+
+describe('hintSchema', () => {
+  it('accepts a normal hint request', () => {
+    const result = hintSchema.safeParse({
+      question: { type: 'short-answer', prompt: 'What is 2+2?' },
+      language: 'en',
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it(`rejects questions whose JSON exceeds ${MAX_HINT_QUESTION_CHARS} chars`, () => {
+    const result = hintSchema.safeParse({
+      question: { prompt: 'x'.repeat(MAX_HINT_QUESTION_CHARS + 1) },
+      language: 'en',
+    })
+    expect(result.success).toBe(false)
+    if (!result.success) {
+      expect(JSON.stringify(result.error.issues)).toContain('too large')
+    }
+  })
+})

backend/src/validators/aiSchemas.ts

@@ -0,0 +1,25 @@
+import { z } from 'zod'
+
+export const MAX_HINT_QUESTION_CHARS = 8000
+
+function serializedSize(value: unknown): number {
+  if (value === undefined || value === null) return 0
+  return JSON.stringify(value).length
+}
+
+export const hintSchema = z
+  .object({
+    question: z.record(z.unknown()),
+    language: z.string().min(1).max(20),
+  })
+  .superRefine((val, ctx) => {
+    if (serializedSize(val.question) > MAX_HINT_QUESTION_CHARS) {
+      ctx.addIssue({
+        code: z.ZodIssueCode.custom,
+        message: 'Question is too large for AI hints',
+        path: ['question'],
+      })
+    }
+  })
+
+export type HintRequestBody = z.infer<typeof hintSchema>

backend/src/validators/authSchemas.test.ts

@@ -1,11 +1,20 @@
 import { describe, it, expect } from 'vitest'
-import { registerSchema, loginSchema, verifyEmailSchema, resetPasswordSchema, updateProfileSchema, changePasswordSchema, forgotPasswordSchema } from './authSchemas'
+import { registerSchema, loginSchema, verifyEmailSchema, resendVerificationSchema, resetPasswordSchema, updateProfileSchema, changePasswordSchema, forgotPasswordSchema } from './authSchemas'
 
 describe('registerSchema', () => {
   it('accepts valid registration', () => {
     const result = registerSchema.safeParse({
       email: 'test@example.com',
-      password: 'password123',
+      password: 'Password123!',
+      displayName: 'Test User',
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts passwords with hash as special character', () => {
+    const result = registerSchema.safeParse({
+      email: 'test@example.com',
+      password: 'Password123#',
       displayName: 'Test User',
     })
     expect(result.success).toBe(true)
@@ -14,7 +23,7 @@ describe('registerSchema', () => {
   it('rejects invalid email', () => {
     const result = registerSchema.safeParse({
       email: 'not-an-email',
-      password: 'password123',
+      password: 'Password123!',
       displayName: 'Test User',
     })
     expect(result.success).toBe(false)
@@ -32,7 +41,7 @@ describe('registerSchema', () => {
   it('rejects empty display name', () => {
     const result = registerSchema.safeParse({
       email: 'test@example.com',
-      password: 'password123',
+      password: 'Password123!',
       displayName: '',
     })
     expect(result.success).toBe(false)
@@ -63,9 +72,16 @@ describe('verifyEmailSchema', () => {
   })
 })
 
+describe('resendVerificationSchema', () => {
+  it('accepts valid email', () => {
+    const result = resendVerificationSchema.safeParse({ email: 'test@example.com' })
+    expect(result.success).toBe(true)
+  })
+})
+
 describe('resetPasswordSchema', () => {
   it('accepts valid reset', () => {
-    const result = resetPasswordSchema.safeParse({ token: 'abc', newPassword: 'newpass123' })
+    const result = resetPasswordSchema.safeParse({ token: 'abc', newPassword: 'NewPass123!' })
     expect(result.success).toBe(true)
   })
 
@@ -91,7 +107,7 @@ describe('changePasswordSchema', () => {
   it('accepts valid change', () => {
     const result = changePasswordSchema.safeParse({
       currentPassword: 'oldpass',
-      newPassword: 'newpass123',
+      newPassword: 'NewPass123!',
     })
     expect(result.success).toBe(true)
   })

backend/src/validators/authSchemas.ts

@@ -1,8 +1,12 @@
 import { z } from 'zod'
 
+const passwordRegex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&#])[A-Za-z\d@$!%*?&#]{8,}$/
+
 export const registerSchema = z.object({
   email: z.string().email().max(255),
-  password: z.string().min(8, 'Password must be at least 8 characters'),
+  password: z.string()
+    .min(8, 'Password must be at least 8 characters')
+    .regex(passwordRegex, 'Password must contain at least one uppercase letter, one lowercase letter, one number, and one special character (@$!%*?&#)'),
   displayName: z.string().min(1, 'Display name is required').max(100),
 })
 
@@ -15,9 +19,15 @@ export const verifyEmailSchema = z.object({
   token: z.string().min(1, 'Token is required'),
 })
 
+export const resendVerificationSchema = z.object({
+  email: z.string().email(),
+})
+
 export const resetPasswordSchema = z.object({
   token: z.string().min(1, 'Token is required'),
-  newPassword: z.string().min(8, 'Password must be at least 8 characters'),
+  newPassword: z.string()
+    .min(8, 'Password must be at least 8 characters')
+    .regex(passwordRegex, 'Password must contain at least one uppercase letter, one lowercase letter, one number, and one special character (@$!%*?&#)'),
 })
 
 export const updateProfileSchema = z.object({
@@ -26,7 +36,9 @@ export const updateProfileSchema = z.object({
 
 export const changePasswordSchema = z.object({
   currentPassword: z.string(),
-  newPassword: z.string().min(8, 'Password must be at least 8 characters'),
+  newPassword: z.string()
+    .min(8, 'Password must be at least 8 characters')
+    .regex(passwordRegex, 'Password must contain at least one uppercase letter, one lowercase letter, one number, and one special character (@$!%*?&#)'),
 })
 
 export const forgotPasswordSchema = z.object({
@@ -36,6 +48,7 @@ export const forgotPasswordSchema = z.object({
 export type RegisterInput = z.infer<typeof registerSchema>
 export type LoginInput = z.infer<typeof loginSchema>
 export type VerifyEmailInput = z.infer<typeof verifyEmailSchema>
+export type ResendVerificationInput = z.infer<typeof resendVerificationSchema>
 export type ResetPasswordInput = z.infer<typeof resetPasswordSchema>
 export type UpdateProfileInput = z.infer<typeof updateProfileSchema>
 export type ChangePasswordInput = z.infer<typeof changePasswordSchema>

backend/src/validators/collectionSchemas.test.ts

@@ -0,0 +1,100 @@
+import { describe, it, expect } from 'vitest'
+import {
+  createCollectionSchema,
+  updateCollectionSchema,
+  collectionIdParamSchema,
+  moveExamSchema,
+} from './collectionSchemas'
+
+describe('createCollectionSchema', () => {
+  it('accepts valid name', () => {
+    const result = createCollectionSchema.safeParse({ name: 'Math 101' })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects empty name', () => {
+    const result = createCollectionSchema.safeParse({ name: '' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects missing name', () => {
+    const result = createCollectionSchema.safeParse({})
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects name longer than 100 chars', () => {
+    const result = createCollectionSchema.safeParse({ name: 'a'.repeat(101) })
+    expect(result.success).toBe(false)
+  })
+
+  it('accepts name at max length (100)', () => {
+    const result = createCollectionSchema.safeParse({ name: 'a'.repeat(100) })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects non-string name', () => {
+    const result = createCollectionSchema.safeParse({ name: 42 })
+    expect(result.success).toBe(false)
+  })
+})
+
+describe('updateCollectionSchema', () => {
+  it('accepts valid name', () => {
+    const result = updateCollectionSchema.safeParse({ name: 'Renamed' })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects empty name', () => {
+    const result = updateCollectionSchema.safeParse({ name: '' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects name over 100 chars', () => {
+    const result = updateCollectionSchema.safeParse({ name: 'b'.repeat(101) })
+    expect(result.success).toBe(false)
+  })
+})
+
+describe('collectionIdParamSchema', () => {
+  it('accepts numeric id', () => {
+    const result = collectionIdParamSchema.safeParse({ id: '12' })
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects non-numeric id', () => {
+    const result = collectionIdParamSchema.safeParse({ id: 'abc' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects empty id', () => {
+    const result = collectionIdParamSchema.safeParse({ id: '' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects negative id string', () => {
+    const result = collectionIdParamSchema.safeParse({ id: '-3' })
+    expect(result.success).toBe(false)
+  })
+})
+
+describe('moveExamSchema', () => {
+  it('accepts numeric collectionId', () => {
+    const result = moveExamSchema.safeParse({ collectionId: 4 })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts null collectionId (moving out of any collection)', () => {
+    const result = moveExamSchema.safeParse({ collectionId: null })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts empty payload (collectionId omitted)', () => {
+    const result = moveExamSchema.safeParse({})
+    expect(result.success).toBe(true)
+  })
+
+  it('rejects string collectionId', () => {
+    const result = moveExamSchema.safeParse({ collectionId: '4' })
+    expect(result.success).toBe(false)
+  })
+})

backend/src/validators/collectionSchemas.ts

@@ -0,0 +1,17 @@
+import { z } from 'zod'
+
+export const createCollectionSchema = z.object({
+  name: z.string().min(1, 'Name is required').max(100),
+})
+
+export const updateCollectionSchema = z.object({
+  name: z.string().min(1, 'Name is required').max(100),
+})
+
+export const collectionIdParamSchema = z.object({
+  id: z.string().regex(/^\d+$/, 'ID must be a number'),
+})
+
+export const moveExamSchema = z.object({
+  collectionId: z.number().nullable().optional(),
+})

backend/src/validators/examSchemas.test.ts

@@ -1,5 +1,13 @@
 import { describe, it, expect } from 'vitest'
-import { examSchema, saveExamSchema, updateExamSchema, examIdParamSchema } from './examSchemas'
+import {
+  examSchema,
+  saveExamSchema,
+  updateExamSchema,
+  examIdParamSchema,
+  favoriteSchema,
+  shareModeSchema,
+  batchDeleteSchema,
+} from './examSchemas'
 
 describe('examSchema', () => {
   it('accepts minimal valid exam', () => {
@@ -10,6 +18,14 @@ describe('examSchema', () => {
     expect(result.success).toBe(true)
   })
 
+  it('rejects empty title', () => {
+    const result = examSchema.safeParse({
+      title: '',
+      questions: [{ id: '1', type: 'essay', prompt: 'Q' }],
+    })
+    expect(result.success).toBe(false)
+  })
+
   it('rejects missing title', () => {
     const result = examSchema.safeParse({
       questions: [{ id: '1', type: 'essay', prompt: 'Q' }],
@@ -41,6 +57,96 @@ describe('examSchema', () => {
     })
     expect(result.success).toBe(true)
   })
+
+  it('accepts each supported question type', () => {
+    const types = [
+      'multiple-choice', 'multiple-select', 'short-answer', 'translation',
+      'math-input', 'essay', 'match', 'order',
+      'fill-in-the-blanks', 'true-false', 'code-submission',
+      'dropdown-completion', 'numeric-range',
+      'dictation', 'grammar-correction', 'flashcard',
+    ]
+    for (const type of types) {
+      const result = examSchema.safeParse({
+        title: 'X',
+        questions: [{ id: '1', type, prompt: 'Q' }],
+      })
+      expect(result.success, `type ${type} should be accepted`).toBe(true)
+    }
+  })
+
+  it('rejects unsupported question type', () => {
+    const result = examSchema.safeParse({
+      title: 'X',
+      questions: [{ id: '1', type: 'file-upload', prompt: 'Q' }],
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('accepts answer as string, array, or record', () => {
+    const variants = ['answer', ['a', 'b'], { left1: 'right1' }]
+    for (const answer of variants) {
+      const result = examSchema.safeParse({
+        title: 'X',
+        questions: [{ id: '1', type: 'short-answer', prompt: 'Q', answer }],
+      })
+      expect(result.success).toBe(true)
+    }
+  })
+
+  it('rejects non-string/array/record/number/boolean answer', () => {
+    const result = examSchema.safeParse({
+      title: 'X',
+      questions: [{ id: '1', type: 'short-answer', prompt: 'Q', answer: null }],
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('accepts null timeLimitMinutes', () => {
+    const result = examSchema.safeParse({
+      title: 'X',
+      timeLimitMinutes: null,
+      questions: [{ id: '1', type: 'essay', prompt: 'Q' }],
+    })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts feedbackMode end and immediate', () => {
+    for (const feedbackMode of ['end', 'immediate'] as const) {
+      const result = examSchema.safeParse({
+        title: 'X',
+        feedbackMode,
+        questions: [{ id: '1', type: 'essay', prompt: 'Q' }],
+      })
+      expect(result.success).toBe(true)
+    }
+  })
+
+  it('rejects invalid feedbackMode', () => {
+    const result = examSchema.safeParse({
+      title: 'X',
+      feedbackMode: 'never',
+      questions: [{ id: '1', type: 'essay', prompt: 'Q' }],
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('accepts question with rich content (image, audio, code, table)', () => {
+    const result = examSchema.safeParse({
+      title: 'Rich',
+      questions: [{
+        id: '1',
+        type: 'multiple-choice',
+        prompt: 'Pick one',
+        image: { src: 'a.png', alt: 'desc', caption: 'cap' },
+        audio: { src: 'a.mp3' },
+        code: { language: 'js', content: 'x=1' },
+        table: { headers: ['a'], rows: [['b']] },
+        choices: [{ id: 'c1', text: 'one' }, { id: 'c2', text: 'two' }],
+      }],
+    })
+    expect(result.success).toBe(true)
+  })
 })
 
 describe('saveExamSchema', () => {
@@ -82,4 +188,59 @@ describe('examIdParamSchema', () => {
     const result = examIdParamSchema.safeParse({ id: 'abc' })
     expect(result.success).toBe(false)
   })
+
+  it('rejects empty id', () => {
+    const result = examIdParamSchema.safeParse({ id: '' })
+    expect(result.success).toBe(false)
+  })
+})
+
+describe('favoriteSchema', () => {
+  it('accepts true', () => {
+    expect(favoriteSchema.safeParse({ isFavorite: true }).success).toBe(true)
+  })
+
+  it('accepts false', () => {
+    expect(favoriteSchema.safeParse({ isFavorite: false }).success).toBe(true)
+  })
+
+  it('rejects non-boolean', () => {
+    expect(favoriteSchema.safeParse({ isFavorite: 'true' }).success).toBe(false)
+  })
+
+  it('rejects missing field', () => {
+    expect(favoriteSchema.safeParse({}).success).toBe(false)
+  })
+})
+
+describe('shareModeSchema', () => {
+  it('accepts view', () => {
+    expect(shareModeSchema.safeParse({ mode: 'view' }).success).toBe(true)
+  })
+
+  it('accepts clone', () => {
+    expect(shareModeSchema.safeParse({ mode: 'clone' }).success).toBe(true)
+  })
+
+  it('rejects unknown mode', () => {
+    expect(shareModeSchema.safeParse({ mode: 'edit' }).success).toBe(false)
+  })
+})
+
+describe('batchDeleteSchema', () => {
+  it('accepts array of ids', () => {
+    expect(batchDeleteSchema.safeParse({ ids: [1, 2, 3] }).success).toBe(true)
+  })
+
+  it('accepts empty array', () => {
+    expect(batchDeleteSchema.safeParse({ ids: [] }).success).toBe(true)
+  })
+
+  it('rejects string ids', () => {
+    expect(batchDeleteSchema.safeParse({ ids: ['1', '2'] }).success).toBe(false)
+  })
+
+  it('rejects missing ids', () => {
+    expect(batchDeleteSchema.safeParse({}).success).toBe(false)
+  })
 })

backend/src/validators/examSchemas.ts

@@ -30,6 +30,33 @@ const questionTableSchema = z.object({
   rows: z.array(z.array(z.string())),
 })
 
+const blankSchema = z.object({
+  id: z.string(),
+  acceptedAnswers: z.array(z.string()),
+  acceptedForms: z.array(z.string()).optional(),
+  caseSensitive: z.boolean().optional(),
+  ignorePunctuation: z.boolean().optional(),
+  ignoreAccents: z.boolean().optional(),
+})
+
+const dropdownSchema = z.object({
+  id: z.string(),
+  options: z.array(choiceSchema),
+  correctOptionId: z.string(),
+})
+
+const codeConfigSchema = z.object({
+  language: z.string(),
+  starterCode: z.string().optional(),
+})
+
+const numericConfigSchema = z.object({
+  answer: z.number(),
+  tolerance: z.number(),
+  min: z.number().optional(),
+  max: z.number().optional(),
+})
+
 const questionSchema = z.object({
   id: z.string(),
   type: z.enum([
@@ -41,6 +68,14 @@ const questionSchema = z.object({
     'essay',
     'match',
     'order',
+    'fill-in-the-blanks',
+    'true-false',
+    'code-submission',
+    'dropdown-completion',
+    'numeric-range',
+    'dictation',
+    'grammar-correction',
+    'flashcard',
   ]),
   category: z.string().optional(),
   points: z.number().optional(),
@@ -51,7 +86,7 @@ const questionSchema = z.object({
   code: questionCodeSchema.optional(),
   table: questionTableSchema.optional(),
   svg: z.string().optional(),
-  answer: z.union([z.string(), z.array(z.string()), z.record(z.string(), z.string())]).optional(),
+  answer: z.union([z.string(), z.array(z.string()), z.record(z.string(), z.string()), z.boolean(), z.number()]).optional(),
   acceptedForms: z.array(z.string()).optional(),
   caseSensitive: z.boolean().optional(),
   ignorePunctuation: z.boolean().optional(),
@@ -64,6 +99,12 @@ const questionSchema = z.object({
   left: z.array(matchItemSchema).optional(),
   right: z.array(matchItemSchema).optional(),
   items: z.array(matchItemSchema).optional(),
+  textSegments: z.array(z.string()).optional(),
+  blanks: z.array(blankSchema).optional(),
+  dropdowns: z.array(dropdownSchema).optional(),
+  codeConfig: codeConfigSchema.optional(),
+  numericConfig: numericConfigSchema.optional(),
+  textToCorrect: z.string().optional(),
 })
 
 export const examSchema = z.object({
@@ -80,14 +121,28 @@ export const examSchema = z.object({
 
 export const saveExamSchema = z.object({
   exam: examSchema,
+  tags: z.array(z.string()).optional(),
 })
 
 export const updateExamSchema = z.object({
   exam: examSchema,
+  tags: z.array(z.string()).optional(),
 })
 
 export const examIdParamSchema = z.object({
   id: z.string().regex(/^\d+$/, 'ID must be a number'),
 })
 
+export const favoriteSchema = z.object({
+  isFavorite: z.boolean(),
+})
+
+export const shareModeSchema = z.object({
+  mode: z.enum(['view', 'clone']),
+})
+
+export const batchDeleteSchema = z.object({
+  ids: z.array(z.number()),
+})
+
 export type ExamInput = z.infer<typeof examSchema>

backend/src/validators/gradeSchemas.test.ts

@@ -0,0 +1,65 @@
+import { describe, it, expect } from 'vitest'
+import {
+  gradeRequestSchema,
+  MAX_GRADE_QUESTION_CHARS,
+  MAX_GRADE_ANSWER_CHARS,
+} from './gradeSchemas.js'
+
+const validBase = {
+  question: { prompt: 'Explain photosynthesis' },
+  answer: 'Plants convert light into chemical energy',
+  language: 'en',
+}
+
+describe('gradeRequestSchema', () => {
+  it('accepts a well-formed grading request', () => {
+    const result = gradeRequestSchema.safeParse({ type: 'essay', ...validBase })
+    expect(result.success).toBe(true)
+  })
+
+  it(`rejects questions whose JSON exceeds ${MAX_GRADE_QUESTION_CHARS} chars`, () => {
+    const result = gradeRequestSchema.safeParse({
+      type: 'essay',
+      question: { prompt: 'x'.repeat(MAX_GRADE_QUESTION_CHARS + 1) },
+      answer: 'irrelevant',
+      language: 'en',
+    })
+    expect(result.success).toBe(false)
+    if (!result.success) {
+      expect(JSON.stringify(result.error.issues)).toContain('too large')
+    }
+  })
+
+  it(`rejects answers whose JSON exceeds ${MAX_GRADE_ANSWER_CHARS} chars`, () => {
+    const result = gradeRequestSchema.safeParse({
+      type: 'essay',
+      question: { prompt: 'small' },
+      answer: 'y'.repeat(MAX_GRADE_ANSWER_CHARS + 1),
+      language: 'en',
+    })
+    expect(result.success).toBe(false)
+    if (!result.success) {
+      expect(JSON.stringify(result.error.issues)).toContain('too large')
+    }
+  })
+
+  it('rejects unknown question types', () => {
+    const result = gradeRequestSchema.safeParse({
+      type: 'flashcard',
+      question: { prompt: 'hi' },
+      answer: 'yo',
+      language: 'en',
+    })
+    expect(result.success).toBe(false)
+  })
+
+  it('bounds the language field', () => {
+    const result = gradeRequestSchema.safeParse({
+      type: 'essay',
+      question: { prompt: 'hi' },
+      answer: 'yo',
+      language: 'l'.repeat(500),
+    })
+    expect(result.success).toBe(false)
+  })
+})

backend/src/validators/gradeSchemas.ts

@@ -0,0 +1,37 @@
+import { z } from 'zod'
+
+/** Serialized size caps: the grading prompt is built from client-supplied
+ * question/answer objects, so these bound what can be billed per request. */
+export const MAX_GRADE_QUESTION_CHARS = 8000
+export const MAX_GRADE_ANSWER_CHARS = 4000
+
+function serializedSize(value: unknown): number {
+  if (value === undefined || value === null) return 0
+  return JSON.stringify(value).length
+}
+
+const gradeRequestBase = z.object({
+  type: z.enum(['essay', 'short-answer', 'translation', 'math', 'ordering', 'match']),
+  question: z.record(z.unknown()),
+  answer: z.unknown(),
+  language: z.string().min(1).max(30),
+})
+
+export const gradeRequestSchema = gradeRequestBase.superRefine((val, ctx) => {
+  if (serializedSize(val.question) > MAX_GRADE_QUESTION_CHARS) {
+    ctx.addIssue({
+      code: z.ZodIssueCode.custom,
+      message: 'Question is too large for AI grading',
+      path: ['question'],
+    })
+  }
+  if (serializedSize(val.answer) > MAX_GRADE_ANSWER_CHARS) {
+    ctx.addIssue({
+      code: z.ZodIssueCode.custom,
+      message: 'Answer is too large for AI grading',
+      path: ['answer'],
+    })
+  }
+})
+
+export type GradeRequestBody = z.infer<typeof gradeRequestSchema>

backend/src/validators/resultSchemas.test.ts

@@ -68,7 +68,7 @@ describe('submitResultSchema', () => {
     expect(result.success).toBe(true)
   })
 
-  it('accepts negative score_points because schema allows any number', () => {
+  it('rejects negative score_points (client-supplied scores are bounded)', () => {
     const result = submitResultSchema.safeParse({
       title: 'My Exam',
       score_points: -1,
@@ -86,7 +86,25 @@ describe('submitResultSchema', () => {
       },
       exam: { title: 'My Exam', questions: [] },
     })
-    expect(result.success).toBe(true)
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects non-integer counts and absurd magnitudes', () => {
+    const base = {
+      title: 'My Exam',
+      score_points: 8,
+      total_points: 10,
+      correct_count: 8,
+      graded_count: 10,
+      elapsed_ms: 120000,
+      state: { currentIdx: 0, answers: {}, flags: {}, notes: '', startedAt: Date.now(), feedbackMode: 'end' },
+      exam: { title: 'My Exam', questions: [] },
+    }
+    expect(submitResultSchema.safeParse({ ...base, correct_count: 1.5 }).success).toBe(false)
+    expect(submitResultSchema.safeParse({ ...base, score_points: 1e12 }).success).toBe(false)
+    expect(submitResultSchema.safeParse({ ...base, elapsed_ms: -5 }).success).toBe(false)
+    expect(submitResultSchema.safeParse({ ...base, exam_id: -3 }).success).toBe(false)
+    expect(submitResultSchema.safeParse({ ...base, title: 't'.repeat(301) }).success).toBe(false)
   })
 
   it('accepts immediate feedback mode', () => {

backend/src/validators/resultSchemas.ts

@@ -1,14 +1,16 @@
 import { z } from 'zod'
 
+// Scores/counts arrive from the client, so they are bounded to keep forged
+// garbage out of analytics while accepting every value honest clients send.
 export const submitResultSchema = z.object({
-  exam_id: z.number().nullable().optional(),
-  title: z.string().min(1),
-  score_points: z.number(),
-  total_points: z.number(),
-  correct_count: z.number(),
-  graded_count: z.number(),
-  passing_score: z.number().optional(),
-  elapsed_ms: z.number(),
+  exam_id: z.number().int().positive().nullable().optional(),
+  title: z.string().min(1).max(300),
+  score_points: z.number().finite().min(0).max(1e9),
+  total_points: z.number().finite().min(0).max(1e9),
+  correct_count: z.number().int().min(0).max(1e6),
+  graded_count: z.number().int().min(0).max(1e6),
+  passing_score: z.number().finite().min(0).max(1e9).optional(),
+  elapsed_ms: z.number().int().min(0).max(2_147_483_647),
   state: z.record(z.unknown()),
   exam: z.record(z.unknown()),
 })

backend/src/validators/setupSchemas.test.ts

@@ -2,34 +2,102 @@ import { describe, it, expect } from 'vitest'
 import { setupSchema, setupStatusSchema } from './setupSchemas'
 
 describe('setupSchema', () => {
-  it('accepts valid setup', () => {
+  const baseValid = {
+    email: 'admin@example.com',
+    password: 'AdminPass123!',
+    displayName: 'Admin',
+  }
+
+  it('accepts minimal valid setup', () => {
+    const result = setupSchema.safeParse(baseValid)
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts passwords with hash as special character', () => {
+    const result = setupSchema.safeParse({ ...baseValid, password: 'AdminPass123#' })
+    expect(result.success).toBe(true)
+  })
+
+  it('accepts full setup including SMTP fields', () => {
     const result = setupSchema.safeParse({
-      email: 'admin@example.com',
-      password: 'adminpass123',
-      displayName: 'Admin',
+      ...baseValid,
       siteTitle: 'BrainWave',
-      language: 'en',
+      language: 'nl',
+      smtpHost: 'smtp.example.com',
+      smtpPort: '587',
+      smtpUser: 'user',
+      smtpPass: 'pass',
+      smtpFrom: 'noreply@example.com',
+      smtpSecure: 'auto',
+      appUrl: 'https://example.com',
     })
     expect(result.success).toBe(true)
   })
 
   it('rejects invalid email', () => {
-    const result = setupSchema.safeParse({
-      email: 'bad',
-      password: 'adminpass123',
-      displayName: 'Admin',
-    })
+    const result = setupSchema.safeParse({ ...baseValid, email: 'bad' })
     expect(result.success).toBe(false)
   })
 
   it('rejects short password', () => {
-    const result = setupSchema.safeParse({
-      email: 'admin@example.com',
-      password: '123',
-      displayName: 'Admin',
-    })
+    const result = setupSchema.safeParse({ ...baseValid, password: '123' })
     expect(result.success).toBe(false)
   })
+
+  it('rejects password missing complexity (no special char)', () => {
+    const result = setupSchema.safeParse({ ...baseValid, password: 'AdminPass123' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects password missing uppercase', () => {
+    const result = setupSchema.safeParse({ ...baseValid, password: 'adminpass123!' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects password missing digit', () => {
+    const result = setupSchema.safeParse({ ...baseValid, password: 'AdminPass!' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects empty displayName', () => {
+    const result = setupSchema.safeParse({ ...baseValid, displayName: '' })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects displayName over 100 chars', () => {
+    const result = setupSchema.safeParse({ ...baseValid, displayName: 'a'.repeat(101) })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects email longer than 255 chars', () => {
+    const longLocal = 'a'.repeat(250)
+    const result = setupSchema.safeParse({ ...baseValid, email: `${longLocal}@x.com` })
+    expect(result.success).toBe(false)
+  })
+
+  it('rejects invalid language', () => {
+    const result = setupSchema.safeParse({ ...baseValid, language: 'fr' })
+    expect(result.success).toBe(false)
+  })
+
+  it('accepts each language enum value', () => {
+    for (const language of ['en', 'nl'] as const) {
+      const result = setupSchema.safeParse({ ...baseValid, language })
+      expect(result.success).toBe(true)
+    }
+  })
+
+  it('rejects invalid smtpSecure value', () => {
+    const result = setupSchema.safeParse({ ...baseValid, smtpSecure: 'maybe' })
+    expect(result.success).toBe(false)
+  })
+
+  it('accepts each smtpSecure enum value', () => {
+    for (const smtpSecure of ['auto', 'true', 'false'] as const) {
+      const result = setupSchema.safeParse({ ...baseValid, smtpSecure })
+      expect(result.success).toBe(true)
+    }
+  })
 })
 
 describe('setupStatusSchema', () => {

backend/src/validators/setupSchemas.ts

@@ -1,8 +1,12 @@
 import { z } from 'zod'
 
+const passwordRegex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&#])[A-Za-z\d@$!%*?&#]{8,}$/
+
 export const setupSchema = z.object({
   email: z.string().email().max(255),
-  password: z.string().min(8, 'Password must be at least 8 characters'),
+  password: z.string()
+    .min(8, 'Password must be at least 8 characters')
+    .regex(passwordRegex, 'Password must contain at least one uppercase letter, one lowercase letter, one number, and one special character (@$!%*?&#)'),
   displayName: z.string().min(1, 'Display name is required').max(100),
   siteTitle: z.string().min(1, 'Site title is required').max(255).optional(),
   language: z.enum(['en', 'nl']).optional(),

backend/tsconfig.json

@@ -16,5 +16,5 @@
     "isolatedModules": true
   },
   "include": ["src/**/*"],
-  "exclude": ["node_modules", "dist"]
+  "exclude": ["node_modules", "dist", "src/**/*.test.ts", "src/**/*.spec.ts"]
 }

backend/vitest.config.ts

@@ -3,5 +3,7 @@ import { defineConfig } from 'vitest/config'
 export default defineConfig({
   test: {
     setupFiles: ['./vitest.setup.ts'],
+    include: ['src/**/*.{test,spec}.{ts,tsx}'],
+    exclude: ['node_modules', 'dist'],
   },
 })

docs/superpowers/plans/2026-08-21-security-audit-fixes.md

@@ -0,0 +1,104 @@
+# Security Audit Fixes Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Fix all vulnerabilities confirmed by the 2026-08-21 full-codebase security audit (5 confirmed ≥8/10 confidence + 6 sub-threshold verified findings).
+
+**Architecture:** Three clusters. (A) Session security: JWTs gain a `tv` (token version) claim; `requireAuth` revalidates the user against SQLite on every request (deleted accounts, demoted roles, password-rotation revocation); logout blacklists until real `exp`. (B) AI cost control: wire the existing-but-dead quota helpers into every provider call path and cap attacker-controlled prompt sizes. (C) Bootstrap & hygiene: make the setup wizard the only admin bootstrap, stop register-time auto-admin, sanitize admin user listings, bound result schemas, enforce view-only share mode server-side, pin SSH host keys in CI.
+
+**Tech Stack:** Express 5, better-sqlite3 (sync), jsonwebtoken 9, zod 3, vitest 4, Gitea Actions.
+
+**Spec:** Security audit report delivered in this session (2026-08-21). Findings referenced below as Vuln N / sub-threshold N.
+
+## Global Constraints
+
+- Do not alter lines containing redacted numeric literals in `userRepo.ts` (`storageQuotaBytes ?? …`) and `migrations.ts` (`storage_quota_bytes … DEFAULT`) — edit around them.
+- Keep HTTP response shapes of AI endpoints unchanged (`{ data, usageTokens }` payloads stay) so the frontend needs no changes.
+- Tests run with `cd backend && npx vitest run`; vitest.setup stubs `JWT_SECRET`, `DB_PATH=:memory:`; `getDb()` runs full migrations on first use.
+- No git commits — user has not requested them; leave changes in working tree.
+- Existing deployments upgrade transparently; all users are logged out once by the new `tv` claim (accepted, noted in final report).
+
+---
+
+### Task 1: Token versioning + DB revalidation (Vuln 3, Vuln 4, sub-threshold 1)
+
+**Files:**
+- Modify: `backend/src/db/migrations.ts` (add column)
+- Modify: `backend/src/utils/tokens.ts` (JwtPayload.tv)
+- Modify: `backend/src/repositories/userRepo.ts` (token_version plumbing)
+- Modify: `backend/src/middleware/auth.ts` (revalidation)
+- Modify: `backend/src/services/authService.ts` (sign with tv, bump on password events)
+- Modify: `backend/src/routes/setup.ts` (sign with tv)
+- Modify: `backend/src/routes/auth.ts` (logout uses decoded exp)
+- Modify: `backend/src/utils/tokenBlacklist.ts` (purge expired rows at init)
+- Test: `backend/src/utils/tokens.test.ts` (update payload fixtures), `backend/src/middleware/auth.test.ts` (new)
+
+**Interfaces:**
+- Produces: `JwtPayload { userId, email, displayName, role, tv }`; `DbUser.token_version: number`; `UpdateUserData.tokenVersion?: number`.
+
+- [ ] **Step 1: Write failing tests** (`auth.test.ts`): valid token passes and `req.user.role` comes from DB; deleted user → 401; tv mismatch → 401. Update `tokens.test.ts` payload fixtures to include `tv: 0` (type error until implemented = failing).
+- [ ] **Step 2: Run** `npx vitest run src/middleware/auth.test.ts src/utils/tokens.test.ts` → FAIL (missing tv / column).
+- [ ] **Step 3: Implement** per code in execution notes: migration guard block; `token_version INTEGER NOT NULL DEFAULT 0`; JwtPayload gains required `tv`; requireAuth loads user via `getUserById`, 401 on missing user, 401 on `user.token_version !== payload.tv`, rebuilds `req.user` from the DB row; changePassword/resetPassword bump tokenVersion; logout blacklists `(decoded.exp ?? now+86400)*1000`; initCache purges expired rows before loading.
+- [ ] **Step 4: Run** → PASS.
+- [ ] **Step 5: Full suite** `npx vitest run` → PASS.
+
+### Task 2: Setup-gated bootstrap, no register auto-admin, enumeration-safe register, last-admin guard (sub-threshold 2, 3, 4)
+
+**Files:**
+- Modify: `backend/src/routes/setup.ts` (status + POST gate on countAdmins)
+- Modify: `backend/src/routes/auth.ts` (drop isFirstUser; last-admin self-delete guard)
+- Modify: `backend/src/services/authService.ts` (register signature, role always 'user', duplicate → generic success after timing-equalized hash)
+- Modify: `backend/src/db/migrations.ts` (remove auto-promote block)
+- Modify: `backend/src/repositories/userRepo.ts` (remove dead promoteFirstUserToAdmin)
+- Test: `backend/src/services/authService.test.ts` (new)
+
+- [ ] **Step 1: Failing tests**: duplicate-email register resolves `{ message }` with no token; fresh register returns token with role 'user'; both take ~equal time (hash-before-check asserted structurally, not by timing).
+- [ ] **Step 2: Run** → FAIL.
+- [ ] **Step 3: Implement**: setup status/gate switch to `countAdmins() > 0`; register drops isFirstUser param, hashes password before duplicate check, returns `{ message: 'Check your inbox…' }` on duplicates; `DELETE /api/auth/me` refuses when `role==='admin' && countAdmins()<=1`; migrations/userRepo promotion code deleted.
+- [ ] **Step 4: Run** → PASS. **Step 5: Full suite** → PASS.
+
+### Task 3: AI quota enforcement + prompt size caps (Vuln 1, Vuln 2)
+
+**Files:**
+- Modify: `backend/src/utils/aiQuota.ts` (add enforceDailyAiQuota throwing AppError 429)
+- Create: `backend/src/validators/gradeSchemas.ts` (schema with serialized-size superRefine caps), `backend/src/validators/aiSchemas.ts` (hintSchema moved + cap)
+- Modify: `backend/src/routes/ai.ts`, `backend/src/routes/grade.ts`, `backend/src/routes/results.ts` (enforce before provider call; recordDailyAiUsage after, using returned usageTokens)
+- Test: `backend/src/utils/aiQuota.test.ts`, `backend/src/validators/gradeSchemas.test.ts`
+
+**Interfaces:**
+- Consumes: `recordDailyAiUsage(userId, getUtcDateKey(), tokens)`; services' existing `AiUsageResult.usageTokens`.
+- Produces: `enforceDailyAiQuota(userId): void` (throws `AppError(429)`).
+
+- [ ] **Step 1: Failing tests**: quota throws 429 when used ≥ limit; passes under limit; passes when limit unset ("0"/absent → null → unlimited). Grade schema rejects question JSON > 8000 chars / answer > 4000 chars.
+- [ ] **Step 2: Run** → FAIL. **Step 3: Implement. Step 4: Run → PASS. Step 5: Full suite → PASS.**
+
+### Task 4: Admin user DTO + result schema bounds (sub-threshold 5, 6)
+
+**Files:**
+- Modify: `backend/src/repositories/userRepo.ts` (`SafeUser`, explicit SELECT columns in listUsers)
+- Modify: `backend/src/validators/resultSchemas.ts` (finite/int/min/max bounds, title ≤300)
+- Test: `backend/src/validators/resultSchemas.test.ts`, repo test for sanitized listing
+
+- [ ] **Step 1: Failing tests**: listUsers never includes password_hash/verify_token/reset_token/reset_expires keys; schema rejects negative counts, non-integers, huge floats, oversized titles.
+- [ ] **Step 2–5:** implement → PASS → full suite PASS.
+
+### Task 5: View-only share clone block (Vuln 5)
+
+**Files:**
+- Modify: `backend/src/routes/share.ts`
+- Test: `backend/src/routes/share.test.ts`
+
+- [ ] Export pure `canClone(shareMode?: string | null): boolean` ('view' → false; 'clone'/null/undefined → true). Failing test first, then guard `if (!canClone(source.share_mode)) throw new AppError(403, 'This exam is shared as view-only and cannot be saved')` before `cloneExam`. PASS + full suite.
+
+### Task 6: CI SSH host-key pinning (sub-threshold 7)
+
+**Files:** Modify `.gitea/workflows/deploy.yml`
+
+- [ ] Replace keyscan step: write `${{ vars.SSH_HOST_PUBLIC_KEY }}` via env-indirection into known_hosts; hard-fail with setup instructions when unset. Validate YAML parses.
+
+### Task 7: Verification
+
+- [ ] `cd backend && npx tsc --noEmit && npx vitest run` — all green.
+- [ ] `cd frontend && npm run build` (or tsc -b) — typecheck green (no frontend changes expected).
+- [ ] Ultracode adversarial review workflow over the full diff; fix anything CONFIRMED.
+- [ ] Final report mapping each finding → fix → evidence.

frontend/package-lock.json

@@ -12,6 +12,7 @@
         "i18next": "^23.16.8",
         "i18next-browser-languagedetector": "^8.0.4",
         "katex": "^0.16.45",
+        "marked": "^18.0.3",
         "react": "^19.2.5",
         "react-dom": "^19.2.5",
         "react-i18next": "^15.4.1",
@@ -2898,6 +2899,18 @@
         "node": ">=10"
       }
     },
+    "node_modules/marked": {
+      "version": "18.0.3",
+      "resolved": "https://registry.npmjs.org/marked/-/marked-18.0.3.tgz",
+      "integrity": "sha512-7VT90JOkDeaRWpfjOReRGPEKn0ecdARBkDGL+tT1wZY0efPPqkUxLUSmzy/C7TIylQYJC9STISEsCHrqb/7VIA==",
+      "license": "MIT",
+      "bin": {
+        "marked": "bin/marked.js"
+      },
+      "engines": {
+        "node": ">= 20"
+      }
+    },
     "node_modules/minimatch": {
       "version": "3.1.5",
       "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.1.5.tgz",

frontend/package.json

@@ -16,6 +16,7 @@
     "i18next": "^23.16.8",
     "i18next-browser-languagedetector": "^8.0.4",
     "katex": "^0.16.45",
+    "marked": "^18.0.3",
     "react": "^19.2.5",
     "react-dom": "^19.2.5",
     "react-i18next": "^15.4.1",

frontend/public/favicon.svg

@@ -1 +1,4 @@
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1.088.89 1.832L25.843 44.94z" style="fill:#000;fill-opacity:1"/></mask><g mask="url(#a)"><g filter="url(#b)"><ellipse cx="5.508" cy="14.704" fill="#ede6ff" rx="5.508" ry="14.704" style="fill:#ede6ff;fill:color(display-p3 .9275 .9033 1);fill-opacity:1" transform="matrix(.00324 1 1 -.00324 -4.47 31.516)"/></g><g filter="url(#c)"><ellipse cx="10.399" cy="29.851" fill="#ede6ff" rx="10.399" ry="29.851" style="fill:#ede6ff;fill:color(display-p3 .9275 .9033 1);fill-opacity:1" transform="matrix(.00324 1 1 -.00324 -39.328 7.883)"/></g><g filter="url(#d)"><ellipse cx="5.508" cy="30.487" fill="#7e14ff" rx="5.508" ry="30.487" style="fill:#7e14ff;fill:color(display-p3 .4922 .0767 1);fill-opacity:1" transform="rotate(89.814 -25.913 -14.639)scale(1 -1)"/></g><g filter="url(#e)"><ellipse cx="5.508" cy="30.599" fill="#7e14ff" rx="5.508" ry="30.599" style="fill:#7e14ff;fill:color(display-p3 .4922 .0767 1);fill-opacity:1" transform="rotate(89.814 -32.644 -3.334)scale(1 -1)"/></g><g 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style="fill:#7e14ff;fill:color(display-p3 .4922 .0767 1);fill-opacity:1" transform="rotate(39.51 .387 8.972)"/></g><g filter="url(#k)"><ellipse cx="47.523" cy="-6.092" fill="#7e14ff" rx="4.407" ry="29.108" style="fill:#7e14ff;fill:color(display-p3 .4922 .0767 1);fill-opacity:1" transform="rotate(37.892 47.523 -6.092)"/></g><g filter="url(#l)"><ellipse cx="41.412" cy="6.333" fill="#47bfff" rx="5.971" ry="9.665" style="fill:#47bfff;fill:color(display-p3 .2799 .748 1);fill-opacity:1" transform="rotate(37.892 41.412 6.333)"/></g><g filter="url(#m)"><ellipse cx="-1.879" cy="38.332" fill="#7e14ff" rx="4.407" ry="29.108" style="fill:#7e14ff;fill:color(display-p3 .4922 .0767 1);fill-opacity:1" transform="rotate(37.892 -1.88 38.332)"/></g><g filter="url(#n)"><ellipse cx="-1.879" cy="38.332" fill="#7e14ff" rx="4.407" ry="29.108" style="fill:#7e14ff;fill:color(display-p3 .4922 .0767 1);fill-opacity:1" transform="rotate(37.892 -1.88 38.332)"/></g><g filter="url(#o)"><ellipse cx="35.651" 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result="shape"/><feGaussianBlur result="effect1_foregroundBlur_2002_17158" stdDeviation="7.659"/></filtLine truncated
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" role="img" aria-label="BrainWave">
+  <rect x="2" y="2" width="20" height="20" rx="5" fill="none" stroke="#1f1f24" stroke-width="2" />
+  <rect x="6" y="6" width="10" height="12" rx="1.5" fill="#1f1f24" />
+</svg>

frontend/src/App.tsx

@@ -35,6 +35,7 @@ import AdminDashboard from "./components/AdminDashboard";
 import SetupWizard from "./components/SetupWizard";
 import Workspace from "./components/Workspace";
 import ExamEditor from "./components/ExamEditor";
+import ShareView from "./components/ShareView";
 
 const withNotes = (state: ExamState): ExamState => ({
   ...state,
@@ -49,6 +50,7 @@ function AppInner() {
   const { pathname } = useLocation();
   const [exam, setExam] = useState<Exam | null>(null);
   const [examState, setExamState] = useState<ExamState | null>(null);
+  const [reviewResultId, setReviewResultId] = useState<number | null>(null);
   const [history, setHistory] = useState<HistoryEntry[]>(() => loadHistory());
   const [authModalOpen, setAuthModalOpen] = useState(false);
   const [userMenuOpen, setUserMenuOpen] = useState(false);
@@ -94,23 +96,29 @@ function AppInner() {
 
   // Bridge: MyResults stores review data in localStorage; load it on /review/:slug
   useEffect(() => {
-    if (pathname.startsWith("/review/") && !exam) {
+    if (pathname.startsWith("/review/")) {
       const reviewExam = localStorage.getItem('brainwave.review.exam')
       const reviewState = localStorage.getItem('brainwave.review.state')
+      const reviewResultIdRaw = localStorage.getItem('brainwave.review.resultId')
       if (reviewExam && reviewState) {
         try {
           const parsedExam = JSON.parse(reviewExam) as Exam
           const parsedState = JSON.parse(reviewState) as ExamState
           setExam(parsedExam)
           setExamState(withNotes(parsedState))
+          if (reviewResultIdRaw) {
+            const id = Number(reviewResultIdRaw)
+            if (Number.isFinite(id) && id > 0) setReviewResultId(id)
+          }
           localStorage.removeItem('brainwave.review.exam')
           localStorage.removeItem('brainwave.review.state')
+          localStorage.removeItem('brainwave.review.resultId')
         } catch {
           // ignore parse errors
         }
       }
     }
-  }, [pathname, exam]);
+  }, [pathname]);
 
   const setExamStateStrict = useCallback<React.Dispatch<React.SetStateAction<ExamState>>>(
     (nextState) => {
@@ -129,7 +137,7 @@ function AppInner() {
     setExamState(withNotes(state));
   };
 
-  const loadExam = (data: Exam, saveToWorkspace = false, examId?: number | null) => {
+  const loadExam = (data: Exam, saveToWorkspace = false, examId?: number | null, isRedo = false) => {
     if (saveToWorkspace && user && isAuthenticated()) {
       examApi.createExam(data)
         .then((res) => {
@@ -156,6 +164,7 @@ function AppInner() {
         revealed: {},
         startedAt: Date.now(),
         feedbackMode: fm,
+        isRedo,
       });
     });
     navigate(`/exam/${getExamUrlId(data)}/q1`);
@@ -195,39 +204,66 @@ function AppInner() {
       state: { ...examState, completedAt },
     };
 
-    if (user && isAuthenticated()) {
-      void resultApi.submitResult({
-        exam_id: savedExamIdRef.current,
-        title: entry.title,
-        score_points: entry.scorePoints,
-        total_points: entry.totalPoints,
-        correct_count: entry.correctCount,
-        graded_count: entry.gradedCount,
-        passing_score: entry.passingScore,
-        elapsed_ms: entry.elapsedMs,
-        state: entry.state as unknown,
-        exam: entry.exam as unknown,
-      }).then((data) => {
-        sessionStorage.setItem('brainwave.pendingResultId', String(data.id));
-      }).catch(() => {
+    // Skip saving to history / API when this is a redo session
+    if (!examState.isRedo) {
+      if (user && isAuthenticated()) {
+        void resultApi.submitResult({
+          exam_id: savedExamIdRef.current,
+          title: entry.title,
+          score_points: entry.scorePoints,
+          total_points: entry.totalPoints,
+          correct_count: entry.correctCount,
+          graded_count: entry.gradedCount,
+          passing_score: entry.passingScore,
+          elapsed_ms: entry.elapsedMs,
+          state: entry.state as unknown,
+          exam: entry.exam as unknown,
+        }).then((data) => {
+          sessionStorage.setItem('brainwave.pendingResultId', String(data.id));
+        }).catch(() => {
+          appendHistory(entry);
+        });
+      } else {
         appendHistory(entry);
-      });
-    } else {
-      appendHistory(entry);
+      }
+
+      setHistory((prev) => [entry, ...prev]);
     }
 
-    setHistory((prev) => [entry, ...prev]);
     clearState();
     setExamState((s) => (s ? { ...s, completedAt } : s));
     navigate("/results");
   }, [exam, examState, user, navigate]);
 
+  const redoFailed = useCallback(() => {
+    if (!exam || !examState) return;
+    const graded = exam.questions.map((q) =>
+      gradeQuestion(q, examState.answers[q.id]),
+    );
+    const failedQuestions = exam.questions
+      .map((q, i) => ({ q, result: graded[i] }))
+      .filter(({ result }) => !result.correct)
+      .map(({ q }) => q);
+
+    if (failedQuestions.length === 0) return;
+
+    // Shuffle failed questions using Fisher-Yates
+    const shuffled = [...failedQuestions];
+    for (let i = shuffled.length - 1; i > 0; i--) {
+      const j = Math.floor(Math.random() * (i + 1));
+      [shuffled[i], shuffled[j]] = [shuffled[j], shuffled[i]];
+    }
+
+    const redoExam: Exam = { ...exam, questions: shuffled };
+    loadExam(redoExam, false, savedExamIdRef.current, true);
+  }, [exam, examState]);
+
   const exit = () => {
     setExam(null);
     setExamState(null);
     savedExamIdRef.current = null;
     sessionStorage.removeItem('brainwave.pendingResultId');
-    navigate("/");
+    navigate(user && isAuthenticated() ? "/workspace" : "/");
   };
 
   const restart = () => {
@@ -261,6 +297,21 @@ function AppInner() {
     }
   };
 
+  const retakeAttempt = (entry: HistoryEntry) => {
+    const remoteId = (entry as HistoryEntry & { _remoteId?: number })._remoteId;
+    if (remoteId && user && isAuthenticated()) {
+      void resultApi.getResult(remoteId)
+        .then((data) => {
+          loadExam(data.exam as unknown as Exam, false, null, false);
+        })
+        .catch(() => {
+          loadExam(entry.exam, false, null, false);
+        });
+    } else {
+      loadExam(entry.exam, false, null, false);
+    }
+  };
+
   const clearAllHistory = () => {
     if (confirm(t('landing.clearHistoryConfirm'))) {
       clearHistory();
@@ -292,7 +343,7 @@ function AppInner() {
   }, [pathname, exam, examState, user, navigate, pendingResultId]);
 
   const handleAuthFlowDone = () => {
-    navigate("/");
+    navigate(user && isAuthenticated() ? "/workspace" : "/");
     setAuthModalOpen(true);
   };
 
@@ -430,13 +481,18 @@ function AppInner() {
         <Route
           path="/"
           element={
-            <Landing
-              onLoadExam={loadExam}
-              history={history}
-              onResume={resume}
-              onClearHistory={clearAllHistory}
-              onReviewAttempt={reviewAttempt}
-            />
+            user && isAuthenticated() ? (
+              <Navigate to="/workspace" replace />
+            ) : (
+              <Landing
+                onLoadExam={loadExam}
+                history={history}
+                onResume={resume}
+                onClearHistory={clearAllHistory}
+                onReviewAttempt={reviewAttempt}
+                onRetakeAttempt={retakeAttempt}
+              />
+            )
           }
         />
         <Route
@@ -461,6 +517,7 @@ function AppInner() {
                 state={examState}
                 onRestart={restart}
                 onExit={exit}
+                onRedoFailed={redoFailed}
                 reviewOnly={false}
               />
             ) : user && isAuthenticated() ? (
@@ -480,6 +537,7 @@ function AppInner() {
                 onRestart={restart}
                 onExit={exit}
                 reviewOnly={true}
+                resultId={reviewResultId}
               />
             ) : (
               <Navigate to="/" replace />
@@ -496,9 +554,10 @@ function AppInner() {
             )
           }
         />
-        <Route path="/workspace" element={<Navigate to="/workspace/exams" replace />} />
+        <Route path="/workspace" element={<Navigate to="/workspace/overview" replace />} />
         <Route path="/workspace/:tab" element={<Workspace onLoadExam={loadExam} />} />
         <Route path="/exam-editor/:id" element={<ExamEditor />} />
+        <Route path="/share/:token" element={<ShareView onLoadExam={loadExam} />} />
         <Route path="*" element={<Navigate to="/" replace />} />
       </Routes>
 

frontend/src/api/adminApi.ts

@@ -1,4 +1,5 @@
 import { apiFetch } from '../utils/api.js'
+import type { GradingResult } from './gradeApi.js'
 
 export interface AdminUser {
   id: number
@@ -42,6 +43,10 @@ export interface SiteSettings {
   smtp_from: string
   smtp_secure: string
   app_url: string
+  ai_provider: string
+  ai_model: string
+  ai_api_key: string
+  ai_base_url: string
 }
 
 export function getStats(): Promise<DashboardStats> {
@@ -90,3 +95,17 @@ export function sendTestEmail(to: string | undefined, smtp: SmtpConfig): Promise
     body: JSON.stringify({ to, smtp }),
   })
 }
+
+export interface AiTestPayload {
+  provider: string
+  apiKey: string
+  model: string
+  baseURL?: string
+}
+
+export function testAiConnection(payload: AiTestPayload): Promise<GradingResult> {
+  return apiFetch('/api/admin/test-ai', {
+    method: 'POST',
+    body: JSON.stringify(payload),
+  })
+}

frontend/src/api/aiApi.ts

@@ -0,0 +1,63 @@
+import { apiFetch } from '../utils/api.js'
+import type { Question, QuestionType } from '../types'
+
+export interface GenerateQuestionsRequest {
+  topic: string
+  type: QuestionType
+  count: number
+  language: string
+  context?: string
+}
+
+export interface GeneratedQuestion extends Omit<Question, 'id'> {
+  id?: string
+}
+
+export interface GenerateQuestionsResponse {
+  questions: GeneratedQuestion[]
+}
+
+export function generateQuestions(req: GenerateQuestionsRequest): Promise<GenerateQuestionsResponse> {
+  return apiFetch('/api/ai/generate-question', {
+    method: 'POST',
+    body: JSON.stringify(req),
+  })
+}
+
+export interface HintRequest {
+  question: Record<string, unknown>
+  language: string
+}
+
+export interface HintResponse {
+  hint: string
+}
+
+export function getHint(req: HintRequest): Promise<HintResponse> {
+  return apiFetch('/api/ai/hint', {
+    method: 'POST',
+    body: JSON.stringify(req),
+  })
+}
+
+export interface TutorChatMessage {
+  role: 'user' | 'assistant'
+  content: string
+}
+
+export interface TutorChatRequest {
+  resultId: number
+  messages: TutorChatMessage[]
+  language: string
+}
+
+export interface TutorChatResponse {
+  reply: string
+}
+
+export function tutorChat(req: TutorChatRequest): Promise<TutorChatResponse> {
+  return apiFetch('/api/ai/tutor-chat', {
+    method: 'POST',
+    body: JSON.stringify(req),
+  })
+}

frontend/src/api/authApi.ts

@@ -6,6 +6,10 @@ export interface User {
   displayName: string
   role: string
   emailVerified?: boolean
+  storageQuotaBytes?: number
+  usedBytes?: number
+  usedPercent?: number
+  plan?: string
 }
 
 export interface AuthResponse {
@@ -34,7 +38,11 @@ export function changePassword(data: { currentPassword: string; newPassword: str
 }
 
 export function verifyEmailToken(token: string): Promise<{ message: string }> {
-  return apiFetch(`/api/auth/verify-email?token=${encodeURIComponent(token)}`)
+  return apiFetch(`/api/auth/verify?token=${encodeURIComponent(token)}`)
+}
+
+export function resendVerification(email: string): Promise<{ message: string }> {
+  return apiFetch('/api/auth/resend-verification', { method: 'POST', body: JSON.stringify({ email }) })
 }
 
 export function forgotPassword(email?: string): Promise<{ message: string }> {
@@ -48,3 +56,7 @@ export function resetPassword(data: { token: string; newPassword: string }): Pro
 export function deleteAccount(): Promise<{ success: boolean }> {
   return apiFetch('/api/auth/me', { method: 'DELETE' })
 }
+
+export function logout(): Promise<void> {
+  return apiFetch('/api/auth/logout', { method: 'POST' })
+}

frontend/src/api/collectionApi.ts

@@ -0,0 +1,29 @@
+import { apiFetch } from '../utils/api.js'
+
+export interface Collection {
+  id: number
+  name: string
+  created_at: number
+  updated_at: number
+  exam_count: number
+}
+
+export function listCollections(): Promise<Collection[]> {
+  return apiFetch('/api/collections')
+}
+
+export function createCollection(name: string): Promise<{ id: number; name: string }> {
+  return apiFetch('/api/collections', { method: 'POST', body: JSON.stringify({ name }) })
+}
+
+export function updateCollection(id: number, name: string): Promise<{ success: boolean }> {
+  return apiFetch(`/api/collections/${id}`, { method: 'PUT', body: JSON.stringify({ name }) })
+}
+
+export function deleteCollection(id: number): Promise<{ success: boolean }> {
+  return apiFetch(`/api/collections/${id}`, { method: 'DELETE' })
+}
+
+export function moveExamToCollection(examId: number, collectionId: number | null): Promise<{ success: boolean }> {
+  return apiFetch(`/api/collections/move/${examId}`, { method: 'POST', body: JSON.stringify({ collectionId }) })
+}

frontend/src/api/examApi.ts

@@ -8,24 +8,85 @@ export interface ExamListItem {
   created_at: number
   updated_at: number
   question_count: number
+  share_token: string | null
+  is_favorite: number
+  tags: string
+  collection_id: number | null
 }
 
 export function listExams(): Promise<ExamListItem[]> {
   return apiFetch('/api/exams')
 }
 
-export function getExam(id: number): Promise<Exam> {
+export function getExam(id: number): Promise<Exam & { tags?: string[] }> {
   return apiFetch(`/api/exams/${id}`)
 }
 
-export function createExam(exam: Exam): Promise<{ id: number; title: string }> {
-  return apiFetch('/api/exams', { method: 'POST', body: JSON.stringify({ exam }) })
+export function createExam(exam: Exam, tags?: string[]): Promise<{ id: number; title: string }> {
+  return apiFetch('/api/exams', { method: 'POST', body: JSON.stringify({ exam, tags }) })
 }
 
-export function updateExam(id: number, exam: Exam): Promise<{ success: boolean }> {
-  return apiFetch(`/api/exams/${id}`, { method: 'PUT', body: JSON.stringify({ exam }) })
+export function updateExam(id: number, exam: Exam, tags?: string[]): Promise<{ success: boolean }> {
+  return apiFetch(`/api/exams/${id}`, { method: 'PUT', body: JSON.stringify({ exam, tags }) })
 }
 
 export function deleteExam(id: number): Promise<{ success: boolean }> {
   return apiFetch(`/api/exams/${id}`, { method: 'DELETE' })
 }
+
+export function shareExam(id: number): Promise<{ shareToken: string }> {
+  return apiFetch(`/api/exams/${id}/share`, { method: 'POST' })
+}
+
+export function unshareExam(id: number): Promise<{ success: boolean }> {
+  return apiFetch(`/api/exams/${id}/unshare`, { method: 'POST' })
+}
+
+export function getSharedExam(token: string): Promise<{ title: string; subtitle: string | null; questionCount: number; exam: unknown; shareMode: string }> {
+  return apiFetch(`/api/share/${token}`)
+}
+
+export function cloneSharedExam(token: string): Promise<{ id: number; title: string }> {
+  return apiFetch(`/api/share/${token}/clone`, { method: 'POST' })
+}
+
+export function setFavorite(id: number, isFavorite: boolean): Promise<{ success: boolean }> {
+  return apiFetch(`/api/exams/${id}/favorite`, { method: 'PATCH', body: JSON.stringify({ isFavorite }) })
+}
+
+export function exportExam(id: number): Promise<Blob> {
+  return fetch(`/api/exams/${id}/export`, {
+    headers: {
+      'Authorization': `Bearer ${localStorage.getItem('brainwave.auth.token') || ''}`,
+    },
+  }).then((res) => {
+    if (!res.ok) throw new Error('Export failed')
+    return res.blob()
+  })
+}
+
+export function duplicateExam(id: number): Promise<{ id: number; title: string }> {
+  return apiFetch(`/api/exams/${id}/duplicate`, { method: 'POST' })
+}
+
+export interface ClonedExamItem {
+  id: number
+  title: string
+  subtitle: string | null
+  created_at: number
+  updated_at: number
+  question_count: number
+  cloned_from_share_token: string
+}
+
+export function listClonedExams(): Promise<ClonedExamItem[]> {
+  return apiFetch('/api/exams/cloned')
+}
+
+export function setShareMode(id: number, mode: 'view' | 'clone'): Promise<{ success: boolean }> {
+  return apiFetch(`/api/exams/${id}/share-mode`, { method: 'PUT', body: JSON.stringify({ mode }) })
+}
+
+export function batchDelete(ids: number[]): Promise<{ deleted: number }> {
+  return apiFetch('/api/exams/batch-delete', { method: 'POST', body: JSON.stringify({ ids }) })
+}

frontend/src/api/gradeApi.ts

@@ -0,0 +1,21 @@
+import { apiFetch } from '../utils/api.js'
+
+export interface GradingResult {
+  suggestedGrade: number
+  feedback: string
+  detail?: unknown
+}
+
+export interface GradeRequest {
+  type: 'essay' | 'short-answer' | 'translation' | 'math' | 'ordering' | 'match'
+  question: Record<string, unknown>
+  answer: unknown
+  language: string
+}
+
+export function gradeQuestion(req: GradeRequest): Promise<GradingResult> {
+  return apiFetch('/api/grade', {
+    method: 'POST',
+    body: JSON.stringify(req),
+  })
+}

frontend/src/api/resultApi.ts

@@ -41,3 +41,31 @@ export function submitResult(data: SubmitResultData): Promise<{ id: number }> {
 export function deleteResult(id: number): Promise<{ success: boolean }> {
   return apiFetch(`/api/results/${id}`, { method: 'DELETE' })
 }
+
+export interface WeakArea {
+  category: string
+  avgScore: number
+  attempts: number
+}
+
+export interface StudyCoachResult {
+  weakAreas: WeakArea[]
+  studyTips: string[]
+  streakDays: number
+  weakestExamId: number | null
+}
+
+export interface ScoreTrend {
+  completed_at: number
+  score_pct: number
+  title: string
+  exam_id: number | null
+}
+
+export function analyzeResults(): Promise<StudyCoachResult> {
+  return apiFetch('/api/results/analyze')
+}
+
+export function getScoreTrends(): Promise<ScoreTrend[]> {
+  return apiFetch('/api/results/trends')
+}

frontend/src/components/AdminDashboard.tsx

@@ -28,6 +28,11 @@ export default function AdminDashboard({ onExit }: Readonly<Props>) {
     text: string;
   } | null>(null);
   const [testEmailSending, setTestEmailSending] = useState(false);
+  const [testAiMsg, setTestAiMsg] = useState<{
+    ok: boolean;
+    text: string;
+  } | null>(null);
+  const [testAiSending, setTestAiSending] = useState(false);
 
   const loadStats = useCallback(async () => {
     try {
@@ -125,6 +130,26 @@ export default function AdminDashboard({ onExit }: Readonly<Props>) {
     }
   };
 
+  const sendTestAi = async () => {
+    if (!settingsDraft) return;
+    setTestAiSending(true);
+    setTestAiMsg(null);
+    try {
+      await adminApi.testAiConnection({
+        provider: settingsDraft.ai_provider,
+        apiKey: settingsDraft.ai_api_key,
+        model: settingsDraft.ai_model || 'gpt-4o-mini',
+        baseURL: settingsDraft.ai_base_url || undefined,
+      });
+      setTestAiMsg({ ok: true, text: t("admin.aiGrading.testSuccess") });
+    } catch (e) {
+      setTestAiMsg({ ok: false, text: (e as Error).message });
+    } finally {
+      setTestAiSending(false);
+      setTimeout(() => setTestAiMsg(null), 6000);
+    }
+  };
+
   const handleUserSearch = (e: React.FormEvent) => {
     e.preventDefault();
     void loadUsers(userSearch);
@@ -591,6 +616,92 @@ export default function AdminDashboard({ onExit }: Readonly<Props>) {
             </div>
           </div>
 
+          <div className="admin-panel">
+            <div className="admin-panel-header">
+              <h3>{t("admin.aiGrading.title")}</h3>
+            </div>
+            <div className="admin-panel-body admin-settings-form">
+              <div className="admin-setting-row">
+                <label className="admin-setting-label" htmlFor="setting-ai-provider">
+                  <span className="admin-setting-title">{t("admin.aiGrading.provider")}</span>
+                </label>
+                <select
+                  id="setting-ai-provider"
+                  className="input admin-setting-input"
+                  value={settingsDraft.ai_provider || ''}
+                  onChange={(e) => updateDraft("ai_provider", e.target.value)}
+                >
+                  <option value="">—</option>
+                  <option value="openai">OpenAI</option>
+                  <option value="openai-compatible">OpenAI-compatible</option>
+                </select>
+              </div>
+              {settingsDraft.ai_provider === 'openai-compatible' && (
+                <div className="admin-setting-row">
+                  <label className="admin-setting-label" htmlFor="setting-ai-base-url">
+                    <span className="admin-setting-title">{t("admin.aiGrading.baseUrl")}</span>
+                    <span className="admin-setting-desc">
+                      {t("admin.aiGrading.baseUrlDesc")}
+                    </span>
+                  </label>
+                  <input
+                    id="setting-ai-base-url"
+                    className="input admin-setting-input"
+                    placeholder="https://api.example.com/v1"
+                    value={settingsDraft.ai_base_url || ''}
+                    onChange={(e) => updateDraft("ai_base_url", e.target.value)}
+                  />
+                </div>
+              )}
+              <div className="admin-setting-row">
+                <label className="admin-setting-label" htmlFor="setting-ai-model">
+                  <span className="admin-setting-title">{t("admin.aiGrading.model")}</span>
+                </label>
+                <input
+                  id="setting-ai-model"
+                  className="input admin-setting-input"
+                  placeholder="gpt-4o-mini"
+                  value={settingsDraft.ai_model || ''}
+                  onChange={(e) => updateDraft("ai_model", e.target.value)}
+                />
+              </div>
+              <div className="admin-setting-row">
+                <label className="admin-setting-label" htmlFor="setting-ai-key">
+                  <span className="admin-setting-title">{t("admin.aiGrading.apiKey")}</span>
+                </label>
+                <input
+                  id="setting-ai-key"
+                  className="input admin-setting-input"
+                  type="password"
+                  autoComplete="off"
+                  value={settingsDraft.ai_api_key || ''}
+                  onChange={(e) => updateDraft("ai_api_key", e.target.value)}
+                />
+              </div>
+              <div className="admin-setting-row admin-setting-row-stacked">
+                <div className="admin-setting-label">
+                  <span className="admin-setting-title">{t("admin.aiGrading.testButton")}</span>
+                </div>
+                <div className="admin-test-email-row">
+                  <button
+                    className="btn btn-sm"
+                    onClick={() => void sendTestAi()}
+                    disabled={testAiSending || !settingsDraft?.ai_provider || !settingsDraft?.ai_api_key || (settingsDraft?.ai_provider === 'openai-compatible' && !settingsDraft?.ai_base_url)}
+                  >
+                    {testAiSending ? t("admin.sending") : t("admin.aiGrading.testButton")}
+                  </button>
+                </div>
+                {testAiMsg && (
+                  <div
+                    className={`admin-alert ${testAiMsg.ok ? "admin-alert-success" : "admin-alert-error"} admin-alert-inline`}
+                  >
+                    {testAiMsg.text}
+                  </div>
+                )}
+              </div>
+            </div>
+          </div>
+
           <div className="admin-panel">
             <div className="admin-panel-header">
               <h3>{t("admin.maintenance")}</h3>

frontend/src/components/AuthModal.tsx

@@ -1,7 +1,8 @@
-import { useState } from 'react'
+import { useEffect, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 import { useAuth } from '../contexts/AuthContext'
 import { ApiError } from '../utils/api'
+import * as authApi from '../api/authApi'
 
 interface Props {
   onClose: () => void
@@ -10,6 +11,9 @@ interface Props {
 
 type Tab = 'login' | 'register'
 
+const VERIFICATION_RESEND_DELAY_MS = 60_000
+const VERIFICATION_REQUIRED_MESSAGE = 'Please verify your email before logging in'
+
 export default function AuthModal({ onClose, onForgotPassword }: Readonly<Props>) {
   const { t } = useTranslation()
   const { login, register } = useAuth()
@@ -20,22 +24,50 @@ export default function AuthModal({ onClose, onForgotPassword }: Readonly<Props>
   const [displayName, setDisplayName] = useState('')
   const [error, setError] = useState<string | null>(null)
   const [success, setSuccess] = useState<string | null>(null)
+  const [notice, setNotice] = useState<string | null>(null)
   const [submitting, setSubmitting] = useState(false)
+  const [resendingVerification, setResendingVerification] = useState(false)
+  const [verificationEmail, setVerificationEmail] = useState('')
+  const [verificationResendAvailableAt, setVerificationResendAvailableAt] = useState<number | null>(null)
+  const [now, setNow] = useState(() => Date.now())
+
+  useEffect(() => {
+    if (!verificationResendAvailableAt) return undefined
+
+    const timer = window.setInterval(() => {
+      setNow(Date.now())
+    }, 1000)
+
+    return () => window.clearInterval(timer)
+  }, [verificationResendAvailableAt])
+
+  const verificationResendSeconds = verificationResendAvailableAt
+    ? Math.max(0, Math.ceil((verificationResendAvailableAt - now) / 1000))
+    : 0
+  const canResendVerification = verificationEmail.length > 0 && verificationResendSeconds === 0 && !resendingVerification
 
   const switchTab = (t: Tab) => {
     setTab(t)
     setError(null)
     setSuccess(null)
+    setNotice(null)
+    setVerificationEmail('')
+    setVerificationResendAvailableAt(null)
   }
 
   const handleLogin = async (e: React.FormEvent) => {
     e.preventDefault()
     setError(null)
+    setNotice(null)
     setSubmitting(true)
     try {
       await login(email, password)
       onClose()
     } catch (err) {
+      if (err instanceof ApiError && err.status === 403 && err.message === VERIFICATION_REQUIRED_MESSAGE) {
+        setVerificationEmail(email)
+        setVerificationResendAvailableAt(Date.now() + VERIFICATION_RESEND_DELAY_MS)
+      }
       setError(err instanceof ApiError ? err.message : t('auth.loginFailed'))
     } finally {
       setSubmitting(false)
@@ -45,6 +77,7 @@ export default function AuthModal({ onClose, onForgotPassword }: Readonly<Props>
   const handleRegister = async (e: React.FormEvent) => {
     e.preventDefault()
     setError(null)
+    setNotice(null)
     if (password !== confirmPassword) {
       setError(t('auth.passwordsDoNotMatch'))
       return
@@ -60,6 +93,23 @@ export default function AuthModal({ onClose, onForgotPassword }: Readonly<Props>
     }
   }
 
+  const handleResendVerification = async () => {
+    if (!canResendVerification) return
+
+    setResendingVerification(true)
+    setNotice(null)
+    setError(null)
+    try {
+      const response = await authApi.resendVerification(verificationEmail)
+      setNotice(response.message)
+      setVerificationResendAvailableAt(Date.now() + VERIFICATION_RESEND_DELAY_MS)
+    } catch (err) {
+      setError(err instanceof ApiError ? err.message : t('auth.requestFailed'))
+    } finally {
+      setResendingVerification(false)
+    }
+  }
+
   return (
     <div className="auth-overlay" onClick={onClose}>
       <div className="auth-modal" onClick={(e) => e.stopPropagation()}>
@@ -94,6 +144,7 @@ export default function AuthModal({ onClose, onForgotPassword }: Readonly<Props>
 
         {error && <div className="auth-error">{error}</div>}
         {success && <div className="auth-success">{success}</div>}
+        {notice && <div className="auth-success">{notice}</div>}
 
         {!success && tab === 'login' && (
           <form onSubmit={(e) => void handleLogin(e)} className="auth-form">
@@ -133,6 +184,25 @@ export default function AuthModal({ onClose, onForgotPassword }: Readonly<Props>
             >
               {t('auth.forgotPassword')}
             </button>
+            {verificationEmail && error === VERIFICATION_REQUIRED_MESSAGE && (
+              <div className="auth-field" style={{ marginTop: 8 }}>
+                <p className="auth-subtitle" style={{ marginBottom: 8 }}>
+                  {t('auth.verificationResendHint')}
+                </p>
+                <button
+                  type="button"
+                  className="btn"
+                  onClick={() => void handleResendVerification()}
+                  disabled={!canResendVerification}
+                >
+                  {resendingVerification
+                    ? t('auth.sending')
+                    : verificationResendSeconds > 0
+                      ? t('auth.resendVerificationLinkIn', { seconds: verificationResendSeconds })
+                      : t('auth.resendVerificationLink')}
+                </button>
+              </div>
+            )}
           </form>
         )}
 

frontend/src/components/ExamEditor.tsx

@@ -2,6 +2,7 @@ import { useState, useEffect, useCallback } from 'react'
 import { useParams, useNavigate } from 'react-router-dom'
 import { useTranslation } from 'react-i18next'
 import * as examApi from '../api/examApi'
+import * as aiApi from '../api/aiApi'
 import type { Exam, Question, QuestionType, Choice } from '../types'
 
 const QUESTION_TYPES: { value: QuestionType; labelKey: string }[] = [
@@ -13,6 +14,14 @@ const QUESTION_TYPES: { value: QuestionType; labelKey: string }[] = [
   { value: 'essay', labelKey: 'editor.essay' },
   { value: 'match', labelKey: 'editor.match' },
   { value: 'order', labelKey: 'editor.order' },
+  { value: 'fill-in-the-blanks', labelKey: 'editor.fillInTheBlanks' },
+  { value: 'true-false', labelKey: 'editor.trueFalse' },
+  { value: 'code-submission', labelKey: 'editor.codeSubmission' },
+  { value: 'dropdown-completion', labelKey: 'editor.dropdownCompletion' },
+  { value: 'numeric-range', labelKey: 'editor.numericRange' },
+  { value: 'dictation', labelKey: 'editor.dictation' },
+  { value: 'grammar-correction', labelKey: 'editor.grammarCorrection' },
+  { value: 'flashcard', labelKey: 'editor.flashcard' },
 ]
 
 const BLANK_EXAM: Exam = {
@@ -39,6 +48,22 @@ function makeBlankQuestion(type: QuestionType, index: number): Question {
       return { ...base, left: [], right: [], answer: {} }
     case 'order':
       return { ...base, items: [], answer: [] }
+    case 'true-false':
+      return { ...base, answer: true }
+    case 'numeric-range':
+      return { ...base, numericConfig: { answer: 0, tolerance: 0 } }
+    case 'fill-in-the-blanks':
+      return { ...base, textSegments: ['The capital of France is ', '.'], blanks: [{ id: 'b1', acceptedAnswers: ['Paris'] }] }
+    case 'dropdown-completion':
+      return { ...base, textSegments: ['The sky is ', ' during the day.'], dropdowns: [{ id: 'd1', options: [{ id: 'a', text: 'blue' }, { id: 'b', text: 'green' }], correctOptionId: 'a' }] }
+    case 'code-submission':
+      return { ...base, codeConfig: { language: 'python', starterCode: '' }, rubric: [] }
+    case 'dictation':
+      return { ...base, audio: { src: '' }, answer: '', acceptedForms: [], caseSensitive: false }
+    case 'grammar-correction':
+      return { ...base, textToCorrect: '', answer: '', acceptedForms: [], caseSensitive: false }
+    case 'flashcard':
+      return { ...base, answer: '' }
     default:
       return base
   }
@@ -58,6 +83,8 @@ export default function ExamEditor() {
   const [saving, setSaving] = useState(false)
   const [saveMsg, setSaveMsg] = useState<string | null>(null)
   const [hasChanges, setHasChanges] = useState(isNew)
+  const [tags, setTags] = useState<string[]>([])
+  const [aiPanelOpen, setAiPanelOpen] = useState(false)
 
   // Load existing exam
   useEffect(() => {
@@ -66,6 +93,7 @@ export default function ExamEditor() {
     examApi.getExam(examId!)
       .then((data) => {
         setExam(data)
+        setTags(data.tags ?? [])
         setHasChanges(false)
       })
       .catch((e) => setError((e as Error).message))
@@ -90,6 +118,22 @@ export default function ExamEditor() {
     setSelectedIdx(exam.questions.length)
   }
 
+  const appendGeneratedQuestions = useCallback((generated: aiApi.GeneratedQuestion[]) => {
+    let firstNewIdx = -1
+    updateExam((draft) => {
+      firstNewIdx = draft.questions.length
+      for (const g of generated) {
+        const idx = draft.questions.length
+        const merged: Question = {
+          ...(g as Omit<Question, 'id'>),
+          id: `q${idx + 1}`,
+        }
+        draft.questions.push(merged)
+      }
+    })
+    if (firstNewIdx >= 0) setSelectedIdx(firstNewIdx)
+  }, [updateExam])
+
   const removeQuestion = (idx: number) => {
     updateExam((draft) => {
       draft.questions.splice(idx, 1)
@@ -113,12 +157,12 @@ export default function ExamEditor() {
     setError(null)
     try {
       if (isNew) {
-        const data = await examApi.createExam(exam)
+        const data = await examApi.createExam(exam, tags)
         setSaveMsg(t('editor.examCreated'))
         setHasChanges(false)
         navigate(`/exam-editor/${data.id}`, { replace: true })
       } else {
-        await examApi.updateExam(examId!, exam)
+        await examApi.updateExam(examId!, exam, tags)
         setSaveMsg(t('editor.examSaved'))
         setHasChanges(false)
       }
@@ -165,6 +209,12 @@ export default function ExamEditor() {
         </div>
       )}
 
+      {!loading && (
+        <div style={{ padding: '8px 16px', borderBottom: '1px solid var(--line-2)', display: 'flex', alignItems: 'center', gap: 8 }}>
+          <TagsEditor tags={tags} onChange={(newTags) => { setTags(newTags); setHasChanges(true) }} />
+        </div>
+      )}
+
       {loading ? (
         <div className="exam-editor-loading">{t('common.loading')}</div>
       ) : (
@@ -194,6 +244,21 @@ export default function ExamEditor() {
 
             <div className="exam-editor-add">
               <div className="sidebar-section-label" style={{ marginTop: 24 }}>{t('editor.addQuestion')}</div>
+              <button
+                className="btn btn-sm"
+                style={{ width: '100%', marginBottom: 8 }}
+                onClick={() => setAiPanelOpen((v) => !v)}
+              >
+                {aiPanelOpen ? t('editor.aiClose') : t('editor.aiGenerate')}
+              </button>
+              {aiPanelOpen && (
+                <AIGeneratePanel
+                  onGenerated={(qs) => {
+                    appendGeneratedQuestions(qs)
+                    setAiPanelOpen(false)
+                  }}
+                />
+              )}
               <div className="exam-editor-type-grid">
                 {QUESTION_TYPES.map((tType) => (
                   <button
@@ -234,6 +299,175 @@ export default function ExamEditor() {
   )
 }
 
+/* ─── Tags Editor ─── */
+
+function TagsEditor({ tags, onChange }: { tags: string[]; onChange: (tags: string[]) => void }) {
+  const { t } = useTranslation()
+  const [input, setInput] = useState('')
+
+  const addTag = () => {
+    const raw = input.trim().toLowerCase().replace(/[^a-z0-9\-_]/g, '')
+    if (!raw) return
+    if (tags.includes(raw)) return
+    onChange([...tags, raw])
+    setInput('')
+  }
+
+  const removeTag = (tag: string) => {
+    onChange(tags.filter((t) => t !== tag))
+  }
+
+  return (
+    <div style={{ display: 'flex', alignItems: 'center', gap: 8, flexWrap: 'wrap', flex: 1 }}>
+      <span style={{ fontSize: 12, color: 'var(--ink-3)' }}>{t('editor.tagsLabel')}</span>
+      {tags.map((tag) => (
+        <span
+          key={tag}
+          style={{
+            fontSize: 11,
+            padding: '2px 8px',
+            borderRadius: 4,
+            background: 'var(--paper)',
+            color: 'var(--ink-3)',
+            border: '1px solid var(--line-2)',
+            display: 'inline-flex',
+            alignItems: 'center',
+            gap: 4,
+          }}
+        >
+          {tag}
+          <button
+            onClick={() => removeTag(tag)}
+            style={{ background: 'none', border: 'none', cursor: 'pointer', padding: 0, fontSize: 11, color: 'var(--wrong)' }}
+          >
+            ✕
+          </button>
+        </span>
+      ))}
+      <div style={{ display: 'flex', gap: 4, alignItems: 'center' }}>
+        <input
+          className="input"
+          value={input}
+          onChange={(e) => setInput(e.target.value)}
+          onKeyDown={(e) => {
+            if (e.key === 'Enter') {
+              e.preventDefault()
+              addTag()
+            }
+          }}
+          placeholder={t('editor.tagsPlaceholder')}
+          style={{ width: 140, fontSize: 12 }}
+        />
+        <button className="btn btn-sm" onClick={addTag} style={{ fontSize: 11 }}>
+          {t('editor.addTag')}
+        </button>
+      </div>
+    </div>
+  )
+}
+
+/* ─── AI Generate Panel ─── */
+
+const AI_GENERATE_TYPES: { value: QuestionType; labelKey: string }[] = QUESTION_TYPES
+
+function AIGeneratePanel({ onGenerated }: { onGenerated: (qs: aiApi.GeneratedQuestion[]) => void }) {
+  const { t, i18n } = useTranslation()
+  const [topic, setTopic] = useState('')
+  const [type, setType] = useState<QuestionType>('short-answer')
+  const [count, setCount] = useState(3)
+  const [context, setContext] = useState('')
+  const [busy, setBusy] = useState(false)
+  const [err, setErr] = useState<string | null>(null)
+
+  const submit = async () => {
+    if (!topic.trim()) {
+      setErr(t('editor.aiTopicRequired'))
+      return
+    }
+    setBusy(true)
+    setErr(null)
+    try {
+      const resp = await aiApi.generateQuestions({
+        topic: topic.trim(),
+        type,
+        count,
+        language: i18n.language || 'en',
+        context: context.trim() || undefined,
+      })
+      onGenerated(resp.questions)
+      setTopic('')
+      setContext('')
+    } catch (e) {
+      setErr((e as Error).message)
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  return (
+    <div
+      style={{
+        padding: 12,
+        marginBottom: 12,
+        border: '1px solid var(--line-2)',
+        borderRadius: 6,
+        background: 'var(--paper)',
+        display: 'flex',
+        flexDirection: 'column',
+        gap: 8,
+      }}
+    >
+      <div style={{ fontSize: 12, color: 'var(--ink-3)' }}>{t('editor.aiPanelTitle')}</div>
+      <input
+        className="input"
+        value={topic}
+        onChange={(e) => setTopic(e.target.value)}
+        placeholder={t('editor.aiTopicPlaceholder')}
+        disabled={busy}
+        style={{ fontSize: 12 }}
+      />
+      <textarea
+        className="input"
+        value={context}
+        onChange={(e) => setContext(e.target.value)}
+        placeholder={t('editor.aiContextPlaceholder')}
+        disabled={busy}
+        rows={3}
+        style={{ fontSize: 12, resize: 'vertical' }}
+      />
+      <div style={{ display: 'flex', gap: 6 }}>
+        <select
+          className="input"
+          value={type}
+          onChange={(e) => setType(e.target.value as QuestionType)}
+          disabled={busy}
+          style={{ flex: 1, fontSize: 12 }}
+        >
+          {AI_GENERATE_TYPES.map((tt) => (
+            <option key={tt.value} value={tt.value}>
+              {t(tt.labelKey)}
+            </option>
+          ))}
+        </select>
+        <input
+          className="input"
+          type="number"
+          min={1}
+          max={10}
+          value={count}
+          onChange={(e) => setCount(Math.max(1, Math.min(10, Number(e.target.value) || 1)))}
+          disabled={busy}
+          style={{ width: 60, fontSize: 12 }}
+        />
+      </div>
+      {err && <div style={{ fontSize: 11, color: 'var(--wrong)' }}>{err}</div>}
+      <button className="btn btn-primary btn-sm" onClick={() => void submit()} disabled={busy}>
+        {busy ? t('editor.aiGenerating') : t('editor.aiGenerateNow')}
+      </button>
+    </div>
+  )
+}
+
 /* ─── Question Editor ─── */
 
 interface QEProps {
@@ -319,6 +553,14 @@ function QuestionEditor({ question, onChange }: QEProps) {
       {question.type === 'essay' && <EssayEditor q={question} onChange={onChange} />}
       {question.type === 'match' && <MatchEditor q={question} onChange={onChange} />}
       {question.type === 'order' && <OrderEditor q={question} onChange={onChange} />}
+      {question.type === 'true-false' && <TrueFalseEditor q={question} onChange={onChange} />}
+      {question.type === 'numeric-range' && <NumericRangeEditor q={question} onChange={onChange} />}
+      {question.type === 'fill-in-the-blanks' && <FillInTheBlanksEditor q={question} onChange={onChange} />}
+      {question.type === 'dropdown-completion' && <DropdownCompletionEditor q={question} onChange={onChange} />}
+      {question.type === 'code-submission' && <CodeSubmissionEditor q={question} onChange={onChange} />}
+      {question.type === 'dictation' && <DictationEditor q={question} onChange={onChange} />}
+      {question.type === 'grammar-correction' && <GrammarCorrectionEditor q={question} onChange={onChange} />}
+      {question.type === 'flashcard' && <FlashcardEditor q={question} onChange={onChange} />}
     </div>
   )
 }
@@ -332,13 +574,12 @@ function MultipleChoiceEditor({ q, onChange }: { q: Question; onChange: QEProps[
   const setAnswer = (a: string) => onChange((q) => { q.answer = a })
 
   const addChoice = () => {
-    const nextId = String.fromCharCode(97 + choices.length) // a, b, c...
+    const nextId = String.fromCharCode(97 + choices.length)
     setChoices([...choices, { id: nextId, text: '' }])
   }
 
   const removeChoice = (idx: number) => {
     const next = choices.filter((_, i) => i !== idx)
-    // Renumber
     const renumbered = next.map((c, i) => ({ ...c, id: String.fromCharCode(97 + i) }))
     setChoices(renumbered)
     if (q.answer === choices[idx]?.id) setAnswer(renumbered[0]?.id ?? '')
@@ -686,6 +927,323 @@ function MatchEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange
   )
 }
 
+/* ─── True/False ─── */
+
+function TrueFalseEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const { t } = useTranslation()
+  return (
+    <div className="question-form-section">
+      <label className="question-form-label">{t('editor.correctAnswer')}</label>
+      <div className="choice-editor-row">
+        <button
+          className={`btn btn-sm${q.answer === true ? ' btn-primary' : ''}`}
+          onClick={() => onChange((q) => { q.answer = true })}
+          type="button"
+        >
+          True
+        </button>
+        <button
+          className={`btn btn-sm${q.answer === false ? ' btn-primary' : ''}`}
+          onClick={() => onChange((q) => { q.answer = false })}
+          type="button"
+        >
+          False
+        </button>
+      </div>
+    </div>
+  )
+}
+
+/* ─── Numeric Range ─── */
+
+function NumericRangeEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const { t } = useTranslation()
+  const cfg = q.numericConfig ?? { answer: 0, tolerance: 0 }
+  return (
+    <div className="question-form-section">
+      <div className="question-form-row-inline">
+        <div>
+          <label className="question-form-label">{t('editor.correctAnswer')}</label>
+          <input
+            className="input"
+            type="number"
+            step="any"
+            value={cfg.answer}
+            onChange={(e) => onChange((q) => { q.numericConfig = { ...cfg, answer: Number(e.target.value) } })}
+          />
+        </div>
+        <div style={{ width: 120 }}>
+          <label className="question-form-label">Tolerance</label>
+          <input
+            className="input"
+            type="number"
+            step="any"
+            min={0}
+            value={cfg.tolerance}
+            onChange={(e) => onChange((q) => { q.numericConfig = { ...cfg, tolerance: Math.max(0, Number(e.target.value)) } })}
+          />
+        </div>
+        <div style={{ width: 120 }}>
+          <label className="question-form-label">Min (opt)</label>
+          <input
+            className="input"
+            type="number"
+            step="any"
+            value={cfg.min ?? ''}
+            onChange={(e) => onChange((q) => { q.numericConfig = { ...cfg, min: e.target.value ? Number(e.target.value) : undefined } })}
+          />
+        </div>
+        <div style={{ width: 120 }}>
+          <label className="question-form-label">Max (opt)</label>
+          <input
+            className="input"
+            type="number"
+            step="any"
+            value={cfg.max ?? ''}
+            onChange={(e) => onChange((q) => { q.numericConfig = { ...cfg, max: e.target.value ? Number(e.target.value) : undefined } })}
+          />
+        </div>
+      </div>
+    </div>
+  )
+}
+
+/* ─── Fill in the Blanks ─── */
+
+function FillInTheBlanksEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const segments = q.textSegments ?? []
+  const blanks = q.blanks ?? []
+
+  const updateSegment = (i: number, text: string) => {
+    const next = [...segments]
+    next[i] = text
+    onChange((q) => { q.textSegments = next })
+  }
+
+  const addBlank = () => {
+    const id = `b${blanks.length + 1}`
+    onChange((q) => {
+      q.textSegments = [...(q.textSegments ?? []), '']
+      q.blanks = [...(q.blanks ?? []), { id, acceptedAnswers: [''] }]
+    })
+  }
+
+  const removeBlank = (idx: number) => {
+    onChange((q) => {
+      q.textSegments = segments.filter((_, i) => i !== idx)
+      q.blanks = blanks.filter((_, i) => i !== idx)
+    })
+  }
+
+  return (
+    <div className="question-form-section">
+      <label className="question-form-label">Text segments & blanks</label>
+      <p className="faint" style={{ fontSize: 12 }}>Text before blank 1, then blank 1 answer, then text before blank 2, etc.</p>
+      {segments.map((seg, i) => (
+        <div key={i} style={{ marginBottom: 12 }}>
+          <div className="choice-editor-row" style={{ marginBottom: 6 }}>
+            <span className="mono faint" style={{ fontSize: 12, width: 60 }}>Text {i + 1}</span>
+            <input
+              className="input"
+              value={seg}
+              onChange={(e) => updateSegment(i, e.target.value)}
+              placeholder={`Text before blank ${i + 1}`}
+            />
+          </div>
+          {i < blanks.length && (
+            <div className="choice-editor-row" style={{ marginBottom: 6, paddingLeft: 20 }}>
+              <span className="mono faint" style={{ fontSize: 12, width: 60 }}>Blank {i + 1}</span>
+              <input
+                className="input"
+                value={blanks[i].acceptedAnswers[0] ?? ''}
+                onChange={(e) => {
+                  const next = [...blanks]
+                  next[i] = { ...next[i], acceptedAnswers: [e.target.value] }
+                  onChange((q) => { q.blanks = next })
+                }}
+                placeholder="Accepted answer"
+              />
+              <button className="btn btn-ghost btn-sm" onClick={() => removeBlank(i)}>✕</button>
+            </div>
+          )}
+        </div>
+      ))}
+      <button className="btn btn-sm" onClick={addBlank} style={{ marginTop: 4 }}>
+        + Add Blank
+      </button>
+    </div>
+  )
+}
+
+/* ─── Dropdown Completion ─── */
+
+function DropdownCompletionEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const segments = q.textSegments ?? []
+  const dropdowns = q.dropdowns ?? []
+
+  const updateSegment = (i: number, text: string) => {
+    const next = [...segments]
+    next[i] = text
+    onChange((q) => { q.textSegments = next })
+  }
+
+  const addDropdown = () => {
+    const id = `d${dropdowns.length + 1}`
+    onChange((q) => {
+      q.textSegments = [...(q.textSegments ?? []), '']
+      q.dropdowns = [...(q.dropdowns ?? []), { id, options: [{ id: 'a', text: '' }, { id: 'b', text: '' }], correctOptionId: 'a' }]
+    })
+  }
+
+  const removeDropdown = (idx: number) => {
+    onChange((q) => {
+      q.textSegments = segments.filter((_, i) => i !== idx)
+      q.dropdowns = dropdowns.filter((_, i) => i !== idx)
+    })
+  }
+
+  return (
+    <div className="question-form-section">
+      <label className="question-form-label">Text segments & dropdowns</label>
+      <p className="faint" style={{ fontSize: 12 }}>Text before dropdown 1, then dropdown 1 options, etc.</p>
+      {segments.map((seg, i) => (
+        <div key={i} style={{ marginBottom: 12 }}>
+          <div className="choice-editor-row" style={{ marginBottom: 6 }}>
+            <span className="mono faint" style={{ fontSize: 12, width: 80 }}>Text {i + 1}</span>
+            <input
+              className="input"
+              value={seg}
+              onChange={(e) => updateSegment(i, e.target.value)}
+              placeholder={`Text before dropdown ${i + 1}`}
+            />
+          </div>
+          {i < dropdowns.length && (
+            <div style={{ paddingLeft: 20, marginBottom: 6 }}>
+              <div className="choice-editor-row" style={{ marginBottom: 4 }}>
+                <span className="mono faint" style={{ fontSize: 12, width: 80 }}>Dropdown {i + 1}</span>
+                <button className="btn btn-ghost btn-sm" onClick={() => removeDropdown(i)}>✕</button>
+              </div>
+              {dropdowns[i].options.map((opt, j) => (
+                <div key={opt.id} className="choice-editor-row" style={{ marginBottom: 4, paddingLeft: 20 }}>
+                  <input
+                    type="radio"
+                    name={`dd-correct-${i}`}
+                    checked={dropdowns[i].correctOptionId === opt.id}
+                    onChange={() => {
+                      const next = [...dropdowns]
+                      next[i] = { ...next[i], correctOptionId: opt.id }
+                      onChange((q) => { q.dropdowns = next })
+                    }}
+                    title="Mark as correct"
+                  />
+                  <span className="mono faint" style={{ fontSize: 13, width: 20 }}>{opt.id}</span>
+                  <input
+                    className="input"
+                    value={opt.text}
+                    onChange={(e) => {
+                      const next = [...dropdowns]
+                      const opts = [...next[i].options]
+                      opts[j] = { ...opts[j], text: e.target.value }
+                      next[i] = { ...next[i], options: opts }
+                      onChange((q) => { q.dropdowns = next })
+                    }}
+                    placeholder={`Option ${opt.id}`}
+                  />
+                </div>
+              ))}
+              <button
+                className="btn btn-sm"
+                style={{ marginLeft: 20, marginTop: 4 }}
+                onClick={() => {
+                  const next = [...dropdowns]
+                  const opts = [...next[i].options]
+                  const nextId = String.fromCharCode(97 + opts.length)
+                  opts.push({ id: nextId, text: '' })
+                  next[i] = { ...next[i], options: opts }
+                  onChange((q) => { q.dropdowns = next })
+                }}
+              >
+                + Add Option
+              </button>
+            </div>
+          )}
+        </div>
+      ))}
+      <button className="btn btn-sm" onClick={addDropdown} style={{ marginTop: 4 }}>
+        + Add Dropdown
+      </button>
+    </div>
+  )
+}
+
+/* ─── Code Submission ─── */
+
+function CodeSubmissionEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const { t } = useTranslation()
+  const cfg = q.codeConfig ?? { language: 'python', starterCode: '' }
+  const rubric = q.rubric ?? []
+
+  return (
+    <div className="question-form-section">
+      <div className="question-form-row-inline">
+        <div style={{ width: 160 }}>
+          <label className="question-form-label">Language</label>
+          <input
+            className="input"
+            value={cfg.language}
+            onChange={(e) => onChange((q) => { q.codeConfig = { ...cfg, language: e.target.value } })}
+            placeholder="e.g. python, javascript"
+          />
+        </div>
+      </div>
+      <div className="question-form-row">
+        <label className="question-form-label">Starter Code</label>
+        <textarea
+          className="textarea mono"
+          value={cfg.starterCode ?? ''}
+          onChange={(e) => onChange((q) => { q.codeConfig = { ...cfg, starterCode: e.target.value } })}
+          rows={6}
+          placeholder="Code shown to the student at start…"
+          spellCheck={false}
+        />
+      </div>
+      <div className="question-form-row">
+        <label className="question-form-label">{t('editor.rubricCriteria')}</label>
+        {rubric.map((item, i) => (
+          <div key={i} className="choice-editor-row" style={{ marginBottom: 6 }}>
+            <input
+              className="input"
+              value={item}
+              onChange={(e) => {
+                const next = [...rubric]
+                next[i] = e.target.value
+                onChange((q) => { q.rubric = next })
+              }}
+              placeholder={t('editor.criterion')}
+            />
+            <button
+              className="btn btn-ghost btn-sm"
+              onClick={() => {
+                const next = rubric.filter((_, idx) => idx !== i)
+                onChange((q) => { q.rubric = next })
+              }}
+            >
+              ✕
+            </button>
+          </div>
+        ))}
+        <button
+          className="btn btn-sm"
+          onClick={() => onChange((q) => { q.rubric = [...(q.rubric ?? []), ''] })}
+          style={{ marginTop: 4 }}
+        >
+          {t('editor.addCriterion')}
+        </button>
+      </div>
+    </div>
+  )
+}
+
 /* ─── Order ─── */
 
 function OrderEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
@@ -752,7 +1310,6 @@ function OrderEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange
           <p className="faint" style={{ fontSize: 12, marginTop: 4 }}>
             {t('editor.correctOrderHint')}
           </p>
-          {/* Sync answer to current item order */}
           <button
             className="btn btn-sm"
             style={{ marginTop: 8 }}
@@ -765,3 +1322,62 @@ function OrderEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange
     </div>
   )
 }
+
+/* ─── Dictation ─── */
+
+function DictationEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const { t } = useTranslation()
+  return (
+    <div className="question-form-section">
+      <div className="question-form-row">
+        <label className="question-form-label">{t('editor.dictation')}</label>
+        <input
+          className="input"
+          value={q.audio?.src ?? ''}
+          onChange={(e) => onChange((q) => { q.audio = { src: e.target.value } })}
+          placeholder="https://example.com/audio.mp3"
+        />
+      </div>
+      <TextAnswerEditor q={q} onChange={onChange} />
+    </div>
+  )
+}
+
+/* ─── Grammar Correction ─── */
+
+function GrammarCorrectionEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const { t } = useTranslation()
+  return (
+    <div className="question-form-section">
+      <div className="question-form-row">
+        <label className="question-form-label">{t('editor.textToCorrect')}</label>
+        <input
+          className="input"
+          value={q.textToCorrect ?? ''}
+          onChange={(e) => onChange((q) => { q.textToCorrect = e.target.value })}
+          placeholder={t('editor.textToCorrectPlaceholder')}
+        />
+      </div>
+      <TextAnswerEditor q={q} onChange={onChange} />
+    </div>
+  )
+}
+
+/* ─── Flashcard ─── */
+
+function FlashcardEditor({ q, onChange }: { q: Question; onChange: QEProps['onChange'] }) {
+  const { t } = useTranslation()
+  return (
+    <div className="question-form-section">
+      <div className="question-form-row">
+        <label className="question-form-label">{t('editor.correctAnswer')}</label>
+        <input
+          className="input"
+          value={(q.answer as string) ?? ''}
+          onChange={(e) => onChange((q) => { q.answer = e.target.value })}
+          placeholder="The answer revealed on the back of the card"
+        />
+      </div>
+    </div>
+  )
+}

frontend/src/components/ExamRunner.tsx

@@ -4,6 +4,7 @@ import { useTranslation } from 'react-i18next'
 import type { Exam, ExamState, Question } from "../types";
 import { gradeQuestion } from "../utils/grading";
 import { formatTime } from "../utils/formatting";
+import * as aiApi from "../api/aiApi";
 import Tex from "./Tex";
 import QuestionMedia from "./QuestionMedia";
 import QuestionRenderer from "./questions/QuestionRenderer";
@@ -27,7 +28,7 @@ export default function ExamRunner({
   onNavigate,
   n,
 }: Readonly<Props>) {
-  const { t } = useTranslation()
+  const { t, i18n } = useTranslation()
   const urlIdx = Math.max(0, (Number((n ?? "").replace(/^q/, "")) || 1) - 1);
   const { answers, flags, startedAt, feedbackMode } = state;
   const currentIdx = urlIdx;
@@ -40,6 +41,35 @@ export default function ExamRunner({
     setRevealed(!!state.revealed?.[q.id]);
   }, [currentIdx, q.id, state.revealed]);
 
+  const [hintCache, setHintCache] = useState<Record<string, string>>({});
+  const [hintLoading, setHintLoading] = useState(false);
+  const [hintError, setHintError] = useState<string | null>(null);
+  const currentHint = hintCache[q.id];
+
+  useEffect(() => {
+    setHintError(null);
+  }, [q.id]);
+
+  const requestHint = async () => {
+    if (currentHint || hintLoading) return;
+    setHintLoading(true);
+    setHintError(null);
+    try {
+      const safeQ: Record<string, unknown> = { ...(q as unknown as Record<string, unknown>) };
+      delete safeQ.answer;
+      delete safeQ.acceptedForms;
+      const res = await aiApi.getHint({
+        question: safeQ,
+        language: i18n.language || 'en',
+      });
+      setHintCache((prev) => ({ ...prev, [q.id]: res.hint }));
+    } catch (e) {
+      setHintError((e as Error).message);
+    } finally {
+      setHintLoading(false);
+    }
+  };
+
   const setAnswer = (val: unknown) =>
     setState((s) => ({ ...s, answers: { ...s.answers, [q.id]: val } }));
 
@@ -212,7 +242,7 @@ export default function ExamRunner({
           </span>
         </header>
 
-        <Tex tag="div" className="q-prompt">
+        <Tex tag="div" className="q-prompt" markdown>
           {q.prompt}
         </Tex>
         <QuestionMedia q={q} />
@@ -225,6 +255,26 @@ export default function ExamRunner({
           graded={graded}
         />
 
+        {(currentHint || hintError) && (
+          <div
+            style={{
+              marginTop: 12,
+              padding: 12,
+              borderLeft: '3px solid var(--accent)',
+              background: 'var(--paper)',
+              fontSize: 13,
+              color: 'var(--ink-2)',
+              borderRadius: 4,
+            }}
+          >
+            <div style={{ fontSize: 11, color: 'var(--ink-3)', marginBottom: 4 }}>
+              {t('exam.hintLabel')}
+            </div>
+            {currentHint && <Tex>{currentHint}</Tex>}
+            {hintError && <span style={{ color: 'var(--wrong)' }}>{hintError}</span>}
+          </div>
+        )}
+
         {graded && result && q.type !== "essay" && (
           <div className={`feedback ${result.correct ? "correct" : "wrong"}`}>
             <div className="feedback-label">
@@ -259,6 +309,20 @@ export default function ExamRunner({
           <button className="btn btn-ghost" onClick={toggleFlag}>
             {flags[q.id] ? t('exam.flagged') : t('exam.flagForReview')}
           </button>
+          {!revealed && (
+            <button
+              className="btn btn-ghost"
+              onClick={() => void requestHint()}
+              disabled={hintLoading || !!currentHint}
+              title={t('exam.hintTitle')}
+            >
+              {hintLoading
+                ? t('exam.hintLoading')
+                : currentHint
+                  ? t('exam.hintShown')
+                  : t('exam.needHint')}
+            </button>
+          )}
           <span className="spacer" />
           {feedbackMode === "immediate" &&
             !revealed &&

frontend/src/components/Landing.tsx

@@ -4,6 +4,7 @@ import type { Exam, HistoryEntry } from '../types'
 import { validateExam, parseExam } from '../utils/validation'
 import { loadState } from '../utils/storage'
 import { formatDate, formatTime } from '../utils/formatting'
+import { downloadInstructions } from '../utils/instructions'
 
 interface Props {
   onLoadExam: (exam: Exam, saveToWorkspace?: boolean) => void
@@ -11,6 +12,7 @@ interface Props {
   onResume: () => void
   onClearHistory: () => void
   onReviewAttempt: (entry: HistoryEntry) => void
+  onRetakeAttempt?: (entry: HistoryEntry) => void
 }
 
 const SAMPLES = [
@@ -19,7 +21,7 @@ const SAMPLES = [
   { path: '/samples/mixed-demo.json', title: 'Mixed Demo — Every Question Type', meta: '4 questions · Untimed · Media', mark: '◇' },
 ]
 
-export default function Landing({ onLoadExam, history, onResume, onClearHistory, onReviewAttempt }: Readonly<Props>) {
+export default function Landing({ onLoadExam, history, onResume, onClearHistory, onReviewAttempt, onRetakeAttempt }: Readonly<Props>) {
   const { t } = useTranslation()
   const [err, setErr] = useState<string | null>(null)
   const [dragOver, setDragOver] = useState(false)
@@ -52,327 +54,6 @@ export default function Landing({ onLoadExam, history, onResume, onClearHistory,
     }
   }
 
-  const downloadInstructions = () => {
-    const content = `BRAINWAVE EXAM JSON — FORMAT GUIDE
-====================================
-Give this document to your preferred LLM (ChatGPT, Claude, Gemini, etc.) along with your exam content,
-and ask it to produce a valid JSON file you can upload to BrainWave.
-
-────────────────────────────────────
-TOP-LEVEL STRUCTURE
-────────────────────────────────────
-{
-  "title": "string (REQUIRED) — The name of the exam",
-  "subtitle": "string (optional) — A short description shown under the title",
-  "author": "string (optional) — Who created the exam",
-  "timeLimitMinutes": number | null (optional) — Time limit in minutes, or null/omit for untimed,
-  "feedbackMode": "end" | "immediate" (optional, default: "end")
-      - "end": students see all feedback after submitting the full exam
-      - "immediate": feedback is shown after each question is answered,
-  "passingScore": number (optional) — Passing percentage, e.g. 70 means 70%,
-  "categories": ["string", ...] (optional) — Category labels for organizing questions,
-  "questions": [ ... ] (REQUIRED) — Array of question objects (see below)
-}
-
-────────────────────────────────────
-QUESTION OBJECT (common fields)
-────────────────────────────────────
-Every question MUST have these fields:
-  "id": "string" — Unique identifier, e.g. "q1", "q2", etc.
-  "type": "string" — One of the supported types listed below
-  "prompt": "string" — The question text (supports LaTeX with $...$ or $$...$$)
-
-Optional fields available on ALL question types:
-  "category": "string" — Which category this question belongs to
-  "points": number — Point value (default: 1)
-  "explanation": "string" — Explanation shown after grading (supports LaTeX)
-  "image": { "src": "URL", "alt": "string", "caption": "string" } — Attach an image
-  "audio": { "src": "URL" } — Attach an audio clip
-  "code": { "language": "string", "content": "string" } — Show a code block
-  "table": { "headers": ["Col1", "Col2"], "rows": [["a","b"], ["c","d"]] } — Show a data table
-  "svg": "string" — Raw SVG markup to display
-
-────────────────────────────────────
-QUESTION TYPES
-────────────────────────────────────
-
-1. MULTIPLE CHOICE ("multiple-choice")
-   Student picks ONE correct answer from a list.
-
-   Required fields:
-     "choices": [{ "id": "a", "text": "Option A" }, { "id": "b", "text": "Option B" }, ...]
-     "answer": "a"  ← the id of the correct choice
-
-   Example:
-   {
-     "id": "q1",
-     "type": "multiple-choice",
-     "prompt": "What is the capital of France?",
-     "choices": [
-       { "id": "a", "text": "London" },
-       { "id": "b", "text": "Paris" },
-       { "id": "c", "text": "Berlin" }
-     ],
-     "answer": "b"
-   }
-
-2. MULTIPLE SELECT ("multiple-select")
-   Student selects ALL correct answers (checkboxes).
-
-   Required fields:
-     "choices": [{ "id": "a", "text": "Option A" }, ...]
-     "answer": ["a", "c"]  ← array of correct choice ids
-
-   Example:
-   {
-     "id": "q2",
-     "type": "multiple-select",
-     "prompt": "Which are prime numbers?",
-     "choices": [
-       { "id": "a", "text": "2" },
-       { "id": "b", "text": "4" },
-       { "id": "c", "text": "7" },
-       { "id": "d", "text": "9" }
-     ],
-     "answer": ["a", "c"]
-   }
-
-3. SHORT ANSWER ("short-answer")
-   Student types a short text answer.
-
-   Required fields:
-     "answer": "string" — The correct answer
-
-   Optional fields:
-     "acceptedForms": ["alt1", "alt2"] — Other accepted answers
-     "caseSensitive": true|false (default: false)
-     "ignorePunctuation": true|false (default: false)
-     "ignoreAccents": true|false (default: false)
-
-   Example:
-   {
-     "id": "q3",
-     "type": "short-answer",
-     "prompt": "What element has the chemical symbol 'O'?",
-     "answer": "Oxygen",
-     "caseSensitive": false
-   }
-
-4. TRANSLATION ("translation")
-   Student translates text between languages.
-
-   Required fields:
-     "answer": "string" — The correct translation
-     "sourceLanguage": "string" — e.g. "English"
-     "targetLanguage": "string" — e.g. "Spanish"
-
-   Optional fields:
-     "acceptedForms": ["alt translation 1", "alt translation 2"]
-     "caseSensitive": true|false
-     "ignorePunctuation": true|false
-     "ignoreAccents": true|false
-
-   Example:
-   {
-     "id": "q4",
-     "type": "translation",
-     "sourceLanguage": "English",
-     "targetLanguage": "Spanish",
-     "prompt": "Translate: \\"Good morning, how are you?\\"",
-     "answer": "Buenos días, ¿cómo estás?",
-     "acceptedForms": ["Buenos dias, como estas"],
-     "caseSensitive": false,
-     "ignorePunctuation": true,
-     "ignoreAccents": true
-   }
-
-5. MATH INPUT ("math-input")
-   Student enters a LaTeX math expression.
-
-   Required fields:
-     "answer": "string" — Correct LaTeX expression
-
-   Optional fields:
-     "acceptedForms": ["alt LaTeX 1", "alt LaTeX 2"]
-
-   Example:
-   {
-     "id": "q5",
-     "type": "math-input",
-     "prompt": "Compute the derivative of $x^3$.",
-     "answer": "3x^2",
-     "acceptedForms": ["3x^{2}", "3 x^2"]
-   }
-
-6. ESSAY ("essay")
-   Student writes a long-form response. Graded manually (always marked "ungraded").
-
-   Optional fields:
-     "minWords": number — Minimum word count required
-     "rubric": ["criterion 1", "criterion 2"] — Grading rubric shown during review
-
-   Example:
-   {
-     "id": "q6",
-     "type": "essay",
-     "prompt": "Discuss the causes of World War I.",
-     "points": 10,
-     "minWords": 100,
-     "rubric": [
-       "Mentions alliance systems",
-       "Discusses assassination of Archduke Franz Ferdinand",
-       "Addresses nationalism and imperialism",
-       "Well-structured argument"
-     ]
-   }
-
-7. MATCH ("match")
-   Student matches items from a left column to items in a right column.
-
-   Required fields:
-     "left":  [{ "id": "l1", "text": "Item A" }, { "id": "l2", "text": "Item B" }, ...]
-     "right": [{ "id": "r1", "text": "Match 1" }, { "id": "r2", "text": "Match 2" }, ...]
-     "answer": { "l1": "r2", "l2": "r1" }  ← maps each left id to its correct right id
-
-   Example:
-   {
-     "id": "q7",
-     "type": "match",
-     "prompt": "Match the country to its capital.",
-     "left": [
-       { "id": "l1", "text": "France" },
-       { "id": "l2", "text": "Japan" },
-       { "id": "l3", "text": "Brazil" }
-     ],
-     "right": [
-       { "id": "r1", "text": "Brasília" },
-       { "id": "r2", "text": "Tokyo" },
-       { "id": "r3", "text": "Paris" }
-     ],
-     "answer": { "l1": "r3", "l2": "r2", "l3": "r1" }
-   }
-
-8. ORDER ("order")
-   Student arranges items in the correct sequence (drag & drop).
-
-   Required fields:
-     "items": [{ "id": "s1", "text": "Step 1" }, { "id": "s2", "text": "Step 2" }, ...]
-     "answer": ["s1", "s2", ...]  ← array of item ids in the correct order
-
-   Example:
-   {
-     "id": "q8",
-     "type": "order",
-     "prompt": "Put these historical events in chronological order.",
-     "items": [
-       { "id": "e1", "text": "Moon landing (1969)" },
-       { "id": "e2", "text": "Fall of the Berlin Wall (1989)" },
-       { "id": "e3", "text": "World Wide Web invented (1991)" },
-       { "id": "e4", "text": "First iPhone released (2007)" }
-     ],
-     "answer": ["e1", "e2", "e3", "e4"]
-   }
-
-────────────────────────────────────
-LATEX SUPPORT
-────────────────────────────────────
-Use LaTeX math in prompts, choices, and explanations:
-  - Inline math:  $x^2 + y^2 = z^2$
-  - Display math: $$\\\\int_0^1 x^2 \\\\, dx = \\\\frac{1}{3}$$
-
-Remember to double-escape backslashes in JSON strings:
-  "prompt": "Evaluate $\\\\frac{d}{dx} x^2$"
-
-────────────────────────────────────
-MEDIA ATTACHMENTS
-────────────────────────────────────
-You can attach images, audio, code blocks, tables, and SVGs to any question.
-Use publicly accessible URLs for image and audio sources.
-
-Image:   "image": { "src": "https://example.com/photo.jpg", "alt": "Description", "caption": "Optional caption" }
-Audio:   "audio": { "src": "https://example.com/clip.mp3" }
-Code:    "code": { "language": "python", "content": "def hello():\\n    print('hi')" }
-Table:   "table": { "headers": ["Name", "Value"], "rows": [["A", "1"], ["B", "2"]] }
-
-────────────────────────────────────
-COMPLETE MINI EXAMPLE
-────────────────────────────────────
-{
-  "title": "Biology 101 — Cell Structure Quiz",
-  "subtitle": "Chapters 3-4 review",
-  "author": "Prof. Smith",
-  "timeLimitMinutes": 15,
-  "feedbackMode": "end",
-  "passingScore": 70,
-  "categories": ["Cells", "Organelles"],
-  "questions": [
-    {
-      "id": "q1",
-      "type": "multiple-choice",
-      "category": "Cells",
-      "points": 2,
-      "prompt": "Which organelle is known as the 'powerhouse of the cell'?",
-      "choices": [
-        { "id": "a", "text": "Nucleus" },
-        { "id": "b", "text": "Mitochondria" },
-        { "id": "c", "text": "Ribosome" },
-        { "id": "d", "text": "Golgi apparatus" }
-      ],
-      "answer": "b",
-      "explanation": "Mitochondria produce ATP through cellular respiration."
-    },
-    {
-      "id": "q2",
-      "type": "short-answer",
-      "category": "Organelles",
-      "points": 1,
-      "prompt": "What is the gel-like fluid inside a cell called?",
-      "answer": "cytoplasm",
-      "acceptedForms": ["Cytoplasm", "cytosol"],
-      "caseSensitive": false
-    },
-    {
-      "id": "q3",
-      "type": "order",
-      "category": "Cells",
-      "points": 3,
-      "prompt": "Order these from smallest to largest:",
-      "items": [
-        { "id": "a", "text": "Atom" },
-        { "id": "b", "text": "Molecule" },
-        { "id": "c", "text": "Organelle" },
-        { "id": "d", "text": "Cell" }
-      ],
-      "answer": ["a", "b", "c", "d"]
-    }
-  ]
-}
-
-────────────────────────────────────
-TIPS FOR LLM PROMPTING
-────────────────────────────────────
-When asking your LLM to create an exam, include:
-  1. This document (paste it in full)
-  2. The subject matter or source material
-  3. How many questions you want
-  4. Which question types to use
-  5. Desired difficulty level
-  6. Whether to include a time limit
-
-Example prompt: "Using the attached format guide, create a 10-question exam on
-World War II. Use a mix of multiple-choice, short-answer, and ordering questions.
-Set a 20-minute time limit. Include explanations for each answer."
-`
-
-    const blob = new Blob([content], { type: 'text/plain' })
-    const url = URL.createObjectURL(blob)
-    const a = document.createElement('a')
-    a.href = url
-    a.download = 'brainwave-exam-format-guide.txt'
-    a.click()
-    URL.revokeObjectURL(url)
-  }
-
   const resumable = loadState()
 
   return (
@@ -483,6 +164,9 @@ Set a 20-minute time limit. Include explanations for each answer."
                 </div>
                 <div className="mono muted" style={{ fontSize: 12 }}>{formatTime(h.elapsedMs)}</div>
                 <div className={`score-pill ${passed ? 'pass' : 'fail'}`}>{pct}%</div>
+                {onRetakeAttempt && (
+                  <button className="btn btn-ghost btn-sm" onClick={() => onRetakeAttempt(h)}>{t('landing.retake')}</button>
+                )}
                 <button className="btn btn-ghost btn-sm" onClick={() => onReviewAttempt(h)}>{t('landing.review')}</button>
               </div>
             )

frontend/src/components/MyExams.tsx

@@ -2,6 +2,7 @@ import { useState, useEffect, useCallback } from 'react'
 import { useNavigate } from 'react-router-dom'
 import { useTranslation } from 'react-i18next'
 import * as examApi from '../api/examApi'
+import * as collectionApi from '../api/collectionApi'
 import type { Exam } from '../types'
 
 interface SavedExam {
@@ -11,27 +12,60 @@ interface SavedExam {
   question_count: number
   created_at: number
   updated_at: number
+  share_token: string | null
+  is_favorite: number
+  tags: string
+  collection_id: number | null
 }
 
 interface Props {
   onLoadExam: (exam: Exam, saveToWorkspace?: boolean, examId?: number | null) => void
 }
 
-export default function MyExams({ onLoadExam }: Props) {
+type CollectionFilter = number | null | 'all' | 'uncategorized'
+
+export default function MyExams({ onLoadExam }: Readonly<Props>) {
   const { t } = useTranslation()
   const navigate = useNavigate()
   const [exams, setExams] = useState<SavedExam[]>([])
+  const [collections, setCollections] = useState<collectionApi.Collection[]>([])
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState<string | null>(null)
   const [deleteConfirm, setDeleteConfirm] = useState<number | null>(null)
   const [startingId, setStartingId] = useState<number | null>(null)
+  const [sharingId, setSharingId] = useState<number | null>(null)
+  const [duplicatingId, setDuplicatingId] = useState<number | null>(null)
+  const [exportingId, setExportingId] = useState<number | null>(null)
+  const [searchQuery, setSearchQuery] = useState('')
+  const [activeFilter, setActiveFilter] = useState<CollectionFilter>('all')
+  const [showNewCollection, setShowNewCollection] = useState(false)
+  const [newCollectionName, setNewCollectionName] = useState('')
+  const [creatingCollection, setCreatingCollection] = useState(false)
+  const [movingExamId, setMovingExamId] = useState<number | null>(null)
+  const [menuOpenId, setMenuOpenId] = useState<number | null>(null)
+  const [menuSection, setMenuSection] = useState<'main' | 'move' | 'share'>('main')
 
-  const loadExams = useCallback(async () => {
+  const closeMenu = () => { setMenuOpenId(null); setMenuSection('main') }
+  const openMenu = (id: number) => { setMenuOpenId(id); setMenuSection('main') }
+  const [editingCollectionId, setEditingCollectionId] = useState<number | null>(null)
+  const [editingCollectionName, setEditingCollectionName] = useState('')
+  const [deleteCollectionId, setDeleteCollectionId] = useState<number | null>(null)
+  const [selectedIds, setSelectedIds] = useState<Set<number>>(new Set())
+  const [batchMoveOpen, setBatchMoveOpen] = useState(false)
+  const [batchDeleting, setBatchDeleting] = useState(false)
+  const [batchExporting, setBatchExporting] = useState(false)
+  const [batchMoving, setBatchMoving] = useState(false)
+
+  const loadData = useCallback(async () => {
     setLoading(true)
     setError(null)
     try {
-      const data = await examApi.listExams()
-      setExams(data)
+      const [examData, collectionData] = await Promise.all([
+        examApi.listExams(),
+        collectionApi.listCollections(),
+      ])
+      setExams(examData)
+      setCollections(collectionData)
     } catch (e) {
       setError((e as Error).message)
     } finally {
@@ -40,14 +74,14 @@ export default function MyExams({ onLoadExam }: Props) {
   }, [])
 
   useEffect(() => {
-    void loadExams()
-  }, [loadExams])
+    void loadData()
+  }, [loadData])
 
   const deleteExam = async (id: number) => {
     try {
       await examApi.deleteExam(id)
       setDeleteConfirm(null)
-      void loadExams()
+      void loadData()
     } catch (e) {
       setError((e as Error).message)
     }
@@ -68,97 +102,725 @@ export default function MyExams({ onLoadExam }: Props) {
     }
   }
 
+  const handleShare = async (id: number) => {
+    setSharingId(id)
+    try {
+      const res = await examApi.shareExam(id)
+      const url = `${window.location.origin}/share/${res.shareToken}`
+      await navigator.clipboard.writeText(url)
+      closeMenu()
+      setExams((prev) => prev.map((e) => (e.id === id ? { ...e, share_token: res.shareToken } : e)))
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setSharingId(null)
+    }
+  }
+
+  const handleUnshare = async (id: number) => {
+    try {
+      await examApi.unshareExam(id)
+      closeMenu()
+      setExams((prev) => prev.map((e) => (e.id === id ? { ...e, share_token: null } : e)))
+    } catch (e) {
+      setError((e as Error).message)
+    }
+  }
+
+  const handleFavorite = async (id: number, isFavorite: boolean) => {
+    try {
+      await examApi.setFavorite(id, isFavorite)
+      setExams((prev) => prev.map((e) => {
+        if (e.id !== id) return e
+        const updated = { ...e, is_favorite: isFavorite ? 1 : 0 }
+        return updated
+      }).sort((a, b) => (b.is_favorite - a.is_favorite) || (b.updated_at - a.updated_at)))
+    } catch (e) {
+      setError((e as Error).message)
+    }
+  }
+
+  const handleExport = async (id: number, title: string) => {
+    setExportingId(id)
+    try {
+      const blob = await examApi.exportExam(id)
+      const url = URL.createObjectURL(blob)
+      const a = document.createElement('a')
+      a.href = url
+      a.download = `${title.replace(/[^a-z0-9]/gi, '_').toLowerCase()}.json`
+      a.click()
+      URL.revokeObjectURL(url)
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setExportingId(null)
+    }
+  }
+
+  const handleDuplicate = async (id: number) => {
+    setDuplicatingId(id)
+    try {
+      await examApi.duplicateExam(id)
+      void loadData()
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setDuplicatingId(null)
+    }
+  }
+
+  const handleCreateCollection = async () => {
+    const name = newCollectionName.trim()
+    if (!name) return
+    setCreatingCollection(true)
+    try {
+      await collectionApi.createCollection(name)
+      setNewCollectionName('')
+      setShowNewCollection(false)
+      void loadData()
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setCreatingCollection(false)
+    }
+  }
+
+  const handleMoveExam = async (examId: number, collectionId: number | null) => {
+    setMovingExamId(examId)
+    try {
+      await collectionApi.moveExamToCollection(examId, collectionId)
+      closeMenu()
+      setExams((prev) => prev.map((e) => e.id === examId ? { ...e, collection_id: collectionId } : e))
+      setCollections((prev) => prev.map((c) => {
+        if (collectionId !== null && c.id === collectionId) return { ...c, exam_count: c.exam_count + 1 }
+        const oldExam = exams.find((e) => e.id === examId)
+        if (oldExam?.collection_id !== null && c.id === oldExam?.collection_id) return { ...c, exam_count: Math.max(0, c.exam_count - 1) }
+        return c
+      }))
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setMovingExamId(null)
+    }
+  }
+
+  const handleRenameCollection = async (id: number) => {
+    const name = editingCollectionName.trim()
+    if (!name) {
+      setEditingCollectionId(null)
+      return
+    }
+    try {
+      await collectionApi.updateCollection(id, name)
+      setCollections((prev) => prev.map((c) => c.id === id ? { ...c, name } : c))
+      setEditingCollectionId(null)
+    } catch (e) {
+      setError((e as Error).message)
+    }
+  }
+
+  const handleDeleteCollection = async (id: number) => {
+    try {
+      await collectionApi.deleteCollection(id)
+      setDeleteCollectionId(null)
+      setExams((prev) => prev.map((e) => e.collection_id === id ? { ...e, collection_id: null } : e))
+      setCollections((prev) => prev.filter((c) => c.id !== id))
+    } catch (e) {
+      setError((e as Error).message)
+    }
+  }
+
+  const toggleSelect = (id: number) => {
+    setSelectedIds((prev) => {
+      const next = new Set(prev)
+      if (next.has(id)) next.delete(id)
+      else next.add(id)
+      return next
+    })
+  }
+
+  const selectAllFiltered = () => {
+    setSelectedIds(new Set(filteredExams.map((e) => e.id)))
+  }
+
+  const clearSelection = () => {
+    setSelectedIds(new Set())
+  }
+
+  const handleBatchDelete = async () => {
+    if (selectedIds.size === 0) return
+    if (!window.confirm(t('workspace.batchDeleteConfirm'))) return
+    setBatchDeleting(true)
+    try {
+      await examApi.batchDelete(Array.from(selectedIds))
+      setSelectedIds(new Set())
+      void loadData()
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setBatchDeleting(false)
+    }
+  }
+
+  const handleBatchExport = async () => {
+    if (selectedIds.size === 0) return
+    setBatchExporting(true)
+    try {
+      for (const id of selectedIds) {
+        const exam = exams.find((e) => e.id === id)
+        if (exam) {
+          const blob = await examApi.exportExam(id)
+          const url = URL.createObjectURL(blob)
+          const a = document.createElement('a')
+          a.href = url
+          a.download = `${exam.title.replace(/[^a-z0-9]/gi, '_').toLowerCase()}.json`
+          document.body.appendChild(a)
+          a.click()
+          document.body.removeChild(a)
+          URL.revokeObjectURL(url)
+        }
+      }
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setBatchExporting(false)
+    }
+  }
+
+  const handleBatchMove = async (collectionId: number | null) => {
+    if (selectedIds.size === 0) return
+    setBatchMoving(true)
+    try {
+      for (const id of selectedIds) {
+        await collectionApi.moveExamToCollection(id, collectionId)
+      }
+      setBatchMoveOpen(false)
+      setSelectedIds(new Set())
+      void loadData()
+    } catch (e) {
+      setError((e as Error).message)
+    } finally {
+      setBatchMoving(false)
+    }
+  }
+
   const formatDate = (ts: number) => {
     const d = new Date(ts * 1000)
     return d.toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' })
   }
 
+  const parseTags = (tagsJson: string): string[] => {
+    try {
+      const parsed = JSON.parse(tagsJson)
+      return Array.isArray(parsed) ? parsed : []
+    } catch {
+      return []
+    }
+  }
+
+  const filteredExams = exams.filter((exam) => {
+    if (!searchQuery.trim()) return true
+    const q = searchQuery.toLowerCase()
+    const tags = parseTags(exam.tags)
+    return (
+      exam.title.toLowerCase().includes(q) ||
+      (exam.subtitle?.toLowerCase().includes(q) ?? false) ||
+      tags.some((t) => t.toLowerCase().includes(q))
+    )
+  }).filter((exam) => {
+    if (activeFilter === 'all') return true
+    if (activeFilter === 'uncategorized') return exam.collection_id === null
+    return exam.collection_id === activeFilter
+  })
+
+  const uncategorizedCount = exams.filter((e) => e.collection_id === null).length
+
   return (
-    <div className="workspace-section fade-in">
-      <div className="workspace-section-header">
-        <div>
-          <div className="workspace-section-eyebrow">{t('workspace.myWorkspace')}</div>
-          <h2 className="workspace-section-title">{t('workspace.myExams')}</h2>
-        </div>
-        <button className="btn btn-primary btn-sm" onClick={createNewExam}>
-          + {t('workspace.newExam')}
-        </button>
-      </div>
-
-      {error && (
-        <div className="workspace-alert workspace-alert-error">
-          <span>{error}</span>
-          <button onClick={() => setError(null)} className="workspace-alert-close">×</button>
-        </div>
-      )}
-
-      {loading ? (
-        <div className="workspace-empty">{t('common.loading')}</div>
-      ) : exams.length === 0 ? (
-        <div className="workspace-empty">
-          <div className="workspace-empty-icon">◇</div>
-          <div className="workspace-empty-title">{t('workspace.noSavedExams')}</div>
-          <div className="workspace-empty-desc">
-            {t('workspace.noSavedExamsDesc')}
-          </div>
-          <button className="btn btn-primary" onClick={createNewExam} style={{ marginTop: 16 }}>
-            {t('workspace.createFirstExam')}
+    <div className="workspace-section fade-in" style={{ display: 'flex', gap: 20 }}>
+      {/* Collections Sidebar */}
+      <div style={{ width: 220, flexShrink: 0 }}>
+        <div style={{ fontSize: 11, fontWeight: 600, textTransform: 'uppercase', letterSpacing: '0.08em', color: 'var(--ink-3)', marginBottom: 10, display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
+          {t('workspace.collections')}
+          <button
+            className="btn btn-ghost btn-sm"
+            style={{ fontSize: 16, padding: '2px 6px', lineHeight: 1 }}
+            onClick={() => setShowNewCollection(true)}
+            title={t('workspace.newCollection')}
+          >
+            +
           </button>
         </div>
-      ) : (
-        <div className="workspace-list">
-          {exams.map((exam) => (
-            <div key={exam.id} className="workspace-card">
-              <div className="workspace-card-body">
-                <div className="workspace-card-title">{exam.title}</div>
-                {exam.subtitle && (
-                  <div className="workspace-card-sub">{exam.subtitle}</div>
-                )}
-                <div className="workspace-card-meta">
-                  <span>{exam.question_count} {exam.question_count === 1 ? t('common.question') : t('common.questions')}</span>
-                  <span>·</span>
-                  <span>{t('workspace.updated')} {formatDate(exam.updated_at)}</span>
+
+        {showNewCollection && (
+          <div style={{ marginBottom: 8, display: 'flex', gap: 4 }}>
+            <input
+              type="text"
+              className="input"
+              placeholder={t('workspace.collectionNamePlaceholder')}
+              value={newCollectionName}
+              onChange={(e) => setNewCollectionName(e.target.value)}
+              onKeyDown={(e) => { if (e.key === 'Enter') void handleCreateCollection() }}
+              style={{ fontSize: 12, padding: '4px 8px', flex: 1 }}
+              autoFocus
+            />
+            <button className="btn btn-sm btn-primary" onClick={() => void handleCreateCollection()} disabled={creatingCollection} style={{ fontSize: 11, padding: '4px 8px' }}>
+              {t('workspace.create')}
+            </button>
+            <button className="btn btn-sm btn-ghost" onClick={() => { setShowNewCollection(false); setNewCollectionName('') }} style={{ fontSize: 11, padding: '4px 8px' }}>
+              {t('common.cancel')}
+            </button>
+          </div>
+        )}
+
+        <div style={{ display: 'flex', flexDirection: 'column', gap: 2 }}>
+          <button
+            className={`btn btn-ghost btn-sm${activeFilter === 'all' ? ' active' : ''}`}
+            onClick={() => setActiveFilter('all')}
+            style={{ justifyContent: 'space-between', textAlign: 'left', fontWeight: activeFilter === 'all' ? 600 : 400 }}
+          >
+            <span>{t('workspace.allExams')}</span>
+            <span className="mono" style={{ fontSize: 11, color: 'var(--ink-3)' }}>{exams.length}</span>
+          </button>
+          <button
+            className={`btn btn-ghost btn-sm${activeFilter === 'uncategorized' ? ' active' : ''}`}
+            onClick={() => setActiveFilter('uncategorized')}
+            style={{ justifyContent: 'space-between', textAlign: 'left', fontWeight: activeFilter === 'uncategorized' ? 600 : 400 }}
+          >
+            <span>{t('workspace.uncategorized')}</span>
+            <span className="mono" style={{ fontSize: 11, color: 'var(--ink-3)' }}>{uncategorizedCount}</span>
+          </button>
+          {collections.map((col) => (
+            <div key={col.id} style={{ position: 'relative' }}>
+              {editingCollectionId === col.id ? (
+                <div style={{ display: 'flex', gap: 4, padding: '2px 0' }}>
+                  <input
+                    type="text"
+                    className="input"
+                    value={editingCollectionName}
+                    onChange={(e) => setEditingCollectionName(e.target.value)}
+                    onKeyDown={(e) => {
+                      if (e.key === 'Enter') void handleRenameCollection(col.id)
+                      if (e.key === 'Escape') setEditingCollectionId(null)
+                    }}
+                    onBlur={() => void handleRenameCollection(col.id)}
+                    style={{ fontSize: 12, padding: '3px 6px', flex: 1 }}
+                    autoFocus
+                  />
                 </div>
-              </div>
-              <div className="workspace-card-actions">
+              ) : (
                 <button
-                  className="btn btn-primary btn-sm"
-                  onClick={() => void startExam(exam.id)}
-                  disabled={startingId === exam.id}
+                  className={`btn btn-ghost btn-sm${activeFilter === col.id ? ' active' : ''}`}
+                  onClick={() => setActiveFilter(col.id)}
+                  onContextMenu={(e) => {
+                    e.preventDefault()
+                    setEditingCollectionName(col.name)
+                    setEditingCollectionId(col.id)
+                  }}
+                  style={{ justifyContent: 'space-between', textAlign: 'left', fontWeight: activeFilter === col.id ? 600 : 400 }}
                 >
-                  {startingId === exam.id ? t('common.loading') : t('workspace.takeExam')}
+                  <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{col.name}</span>
+                  <span className="mono" style={{ fontSize: 11, color: 'var(--ink-3)', flexShrink: 0 }}>{col.exam_count}</span>
                 </button>
-                <button
-                  className="btn btn-sm"
-                  onClick={() => navigate(`/exam-editor/${exam.id}`)}
-                  disabled={startingId === exam.id}
-                >
-                  {t('common.edit')}
-                </button>
-                {deleteConfirm === exam.id ? (
-                  <div className="workspace-delete-confirm">
-                    <button className="btn btn-sm admin-btn-danger" onClick={() => void deleteExam(exam.id)}>
+              )}
+              {activeFilter === col.id && editingCollectionId !== col.id && (
+                <div style={{ display: 'flex', gap: 4, padding: '0 8px 4px', marginTop: -2 }}>
+                  <button className="btn btn-ghost btn-sm" style={{ fontSize: 10, padding: '2px 6px' }} onClick={() => { setEditingCollectionName(col.name); setEditingCollectionId(col.id) }}>
+                    {t('workspace.rename')}
+                  </button>
+                  <button className="btn btn-ghost btn-sm admin-btn-danger-ghost" style={{ fontSize: 10, padding: '2px 6px' }} onClick={() => setDeleteCollectionId(col.id)}>
+                    {t('common.delete')}
+                  </button>
+                </div>
+              )}
+              {deleteCollectionId === col.id && (
+                <div style={{ padding: '4px 8px', fontSize: 11, background: 'var(--wrong-weak)', borderRadius: 6, margin: '2px 0' }}>
+                  <div style={{ marginBottom: 4 }}>{t('workspace.deleteCollectionConfirm')}</div>
+                  <div style={{ display: 'flex', gap: 4 }}>
+                    <button className="btn btn-sm admin-btn-danger" style={{ fontSize: 10, padding: '2px 8px' }} onClick={() => void handleDeleteCollection(col.id)}>
                       {t('common.confirm')}
                     </button>
-                    <button className="btn btn-ghost btn-sm" onClick={() => setDeleteConfirm(null)}>
+                    <button className="btn btn-sm btn-ghost" style={{ fontSize: 10, padding: '2px 8px' }} onClick={() => setDeleteCollectionId(null)}>
                       {t('common.cancel')}
                     </button>
                   </div>
-                ) : (
-                  <button
-                    className="btn btn-ghost btn-sm admin-btn-danger-ghost"
-                    onClick={() => setDeleteConfirm(exam.id)}
-                    title={t('common.delete')}
-                    disabled={startingId === exam.id}
-                  >
-                    ✕
-                  </button>
-                )}
-              </div>
+                </div>
+              )}
             </div>
           ))}
         </div>
-      )}
+      </div>
+
+      {/* Exams List */}
+      <div style={{ flex: 1, minWidth: 0 }}>
+        <div className="workspace-section-header">
+          <div>
+            <div className="workspace-section-eyebrow">{t('workspace.myWorkspace')}</div>
+            <h2 className="workspace-section-title">{t('workspace.myExams')}</h2>
+          </div>
+          <button className="btn btn-primary btn-sm" onClick={createNewExam}>
+            + {t('workspace.newExam')}
+          </button>
+        </div>
+
+        {/* Search */}
+        <div style={{ marginBottom: 16 }}>
+          <input
+            type="text"
+            className="input"
+            placeholder={t('workspace.searchExams')}
+            value={searchQuery}
+            onChange={(e) => setSearchQuery(e.target.value)}
+            style={{ maxWidth: 400 }}
+          />
+        </div>
+
+        {/* Batch toolbar */}
+        {!loading && filteredExams.length > 0 && (
+          <div style={{ display: 'flex', alignItems: 'center', gap: 8, marginBottom: 12, flexWrap: 'wrap' }}>
+            <label style={{ display: 'flex', alignItems: 'center', gap: 6, fontSize: 13, cursor: 'pointer', userSelect: 'none' }}>
+              <input
+                type="checkbox"
+                checked={selectedIds.size > 0 && selectedIds.size === filteredExams.length}
+                onChange={() => {
+                  if (selectedIds.size === filteredExams.length) clearSelection()
+                  else selectAllFiltered()
+                }}
+                ref={(el) => {
+                  if (el) el.indeterminate = selectedIds.size > 0 && selectedIds.size < filteredExams.length
+                }}
+              />
+              {selectedIds.size === 0 ? t('workspace.batchSelectAll') : t('workspace.batchSelected', { count: selectedIds.size })}
+            </label>
+            {selectedIds.size > 0 && (
+              <>
+                <div style={{ width: 1, height: 16, background: 'var(--line-2)' }} />
+                <button
+                  className="btn btn-sm admin-btn-danger-ghost"
+                  onClick={() => void handleBatchDelete()}
+                  disabled={batchDeleting}
+                  style={{ fontSize: 12 }}
+                >
+                  {batchDeleting ? t('common.loading') : `${t('common.delete')} (${selectedIds.size})`}
+                </button>
+                <button
+                  className="btn btn-sm btn-ghost"
+                  onClick={() => void handleBatchExport()}
+                  disabled={batchExporting}
+                  style={{ fontSize: 12 }}
+                >
+                  {batchExporting ? t('common.loading') : `${t('workspace.export')} (${selectedIds.size})`}
+                </button>
+                <div style={{ position: 'relative' }}>
+                  <button
+                    className="btn btn-sm btn-ghost"
+                    onClick={() => setBatchMoveOpen((v) => !v)}
+                    disabled={batchMoving}
+                    style={{ fontSize: 12 }}
+                  >
+                    {batchMoving ? t('common.loading') : `${t('workspace.moveTo')} (${selectedIds.size})`}
+                  </button>
+                  {batchMoveOpen && (
+                    <div
+                      style={{
+                        position: 'absolute',
+                        left: 0,
+                        top: 'calc(100% + 4px)',
+                        zIndex: 10,
+                        minWidth: 180,
+                        background: 'var(--paper)',
+                        border: '1px solid var(--line-2)',
+                        borderRadius: 8,
+                        boxShadow: 'var(--shadow-md)',
+                        padding: '6px 0',
+                      }}
+                    >
+                      <button
+                        className="user-menu-item"
+                        style={{ fontSize: 13 }}
+                        onClick={() => void handleBatchMove(null)}
+                      >
+                        {t('workspace.uncategorized')}
+                      </button>
+                      {collections.map((col) => (
+                        <button
+                          key={col.id}
+                          className="user-menu-item"
+                          style={{ fontSize: 13 }}
+                          onClick={() => void handleBatchMove(col.id)}
+                        >
+                          {col.name}
+                        </button>
+                      ))}
+                    </div>
+                  )}
+                </div>
+              </>
+            )}
+          </div>
+        )}
+
+        {error && (
+          <div className="workspace-alert workspace-alert-error">
+            <span>{error}</span>
+            <button onClick={() => setError(null)} className="workspace-alert-close">×</button>
+          </div>
+        )}
+
+        {loading ? (
+          <div className="workspace-empty">{t('common.loading')}</div>
+        ) : filteredExams.length === 0 ? (
+          <div className="workspace-empty">
+            <div className="workspace-empty-icon">◇</div>
+            <div className="workspace-empty-title">
+              {searchQuery || activeFilter !== 'all' ? t('workspace.noSearchResults') : t('workspace.noSavedExams')}
+            </div>
+            <div className="workspace-empty-desc">
+              {searchQuery || activeFilter !== 'all' ? t('workspace.noSearchResultsDesc') : t('workspace.noSavedExamsDesc')}
+            </div>
+            {!searchQuery && activeFilter === 'all' && (
+              <button className="btn btn-primary" onClick={createNewExam} style={{ marginTop: 16 }}>
+                {t('workspace.createFirstExam')}
+              </button>
+            )}
+          </div>
+        ) : (
+          <div className="workspace-list">
+            {filteredExams.map((exam) => {
+              const tags = parseTags(exam.tags)
+              return (
+                <div key={exam.id} className={`workspace-card${exam.is_favorite ? ' workspace-card-favorite' : ''}`}>
+                  <div className="workspace-card-body">
+                    <div style={{ display: 'flex', alignItems: 'center', gap: 8 }}>
+                      <input
+                        type="checkbox"
+                        checked={selectedIds.has(exam.id)}
+                        onChange={() => toggleSelect(exam.id)}
+                        style={{ cursor: 'pointer' }}
+                      />
+                      <button
+                        className="btn btn-ghost btn-sm"
+                        onClick={() => void handleFavorite(exam.id, !exam.is_favorite)}
+                        title={exam.is_favorite ? t('workspace.unpin') : t('workspace.pin')}
+                        style={{ fontSize: 16, padding: '2px 6px', lineHeight: 1 }}
+                      >
+                        {exam.is_favorite ? '★' : '☆'}
+                      </button>
+                      <div className="workspace-card-title">{exam.title}</div>
+                    </div>
+                    {exam.subtitle && (
+                      <div className="workspace-card-sub">{exam.subtitle}</div>
+                    )}
+                    <div className="workspace-card-meta">
+                      <span>{exam.question_count} {exam.question_count === 1 ? t('common.question') : t('common.questions')}</span>
+                      <span>·</span>
+                      <span>{t('workspace.updated')} {formatDate(exam.updated_at)}</span>
+                    </div>
+                    {tags.length > 0 && (
+                      <div style={{ display: 'flex', gap: 6, marginTop: 6, flexWrap: 'wrap' }}>
+                        {tags.map((tag) => (
+                          <span
+                            key={tag}
+                            style={{
+                              fontSize: 11,
+                              padding: '2px 8px',
+                              borderRadius: 4,
+                              background: 'var(--paper)',
+                              color: 'var(--ink-3)',
+                              border: '1px solid var(--line-2)',
+                            }}
+                          >
+                            {tag}
+                          </span>
+                        ))}
+                      </div>
+                    )}
+                  </div>
+                  <div className="workspace-card-actions">
+                    {deleteConfirm === exam.id ? (
+                      <div className="workspace-delete-confirm">
+                        <span style={{ fontSize: 13, color: 'var(--ink-3)', marginRight: 4 }}>
+                          {t('workspace.batchDeleteConfirm')}
+                        </span>
+                        <button className="btn btn-sm admin-btn-danger" onClick={() => void deleteExam(exam.id)}>
+                          {t('common.confirm')}
+                        </button>
+                        <button className="btn btn-ghost btn-sm" onClick={() => setDeleteConfirm(null)}>
+                          {t('common.cancel')}
+                        </button>
+                      </div>
+                    ) : (
+                      <>
+                        <button
+                          className="btn btn-primary btn-sm"
+                          onClick={() => void startExam(exam.id)}
+                          disabled={startingId === exam.id}
+                        >
+                          {startingId === exam.id ? t('common.loading') : t('workspace.takeExam')}
+                        </button>
+                        <button
+                          className="btn btn-sm"
+                          onClick={() => navigate(`/exam-editor/${exam.id}`)}
+                          disabled={startingId === exam.id}
+                        >
+                          {t('common.edit')}
+                        </button>
+                        <div style={{ position: 'relative' }}>
+                          <button
+                            className="btn btn-ghost btn-sm workspace-menu-trigger"
+                            onClick={() => menuOpenId === exam.id ? closeMenu() : openMenu(exam.id)}
+                            disabled={startingId === exam.id}
+                            title="More actions"
+                            aria-label="More actions"
+                            aria-haspopup="menu"
+                            aria-expanded={menuOpenId === exam.id}
+                          >
+                            ⋯
+                          </button>
+                          {menuOpenId === exam.id && (
+                            <>
+                              <button
+                                className="workspace-menu-backdrop"
+                                onClick={closeMenu}
+                                aria-label="Close menu"
+                                tabIndex={-1}
+                              />
+                              <div className="workspace-menu" role="menu">
+                                {menuSection === 'main' && (
+                                  <>
+                                    <button
+                                      className="user-menu-item workspace-menu-item"
+                                      onClick={() => { closeMenu(); void handleDuplicate(exam.id) }}
+                                      disabled={duplicatingId === exam.id}
+                                    >
+                                      <span className="workspace-menu-icon">⧉</span>
+                                      <span>{duplicatingId === exam.id ? t('common.loading') : t('workspace.duplicate')}</span>
+                                    </button>
+                                    <button
+                                      className="user-menu-item workspace-menu-item"
+                                      onClick={() => { closeMenu(); void handleExport(exam.id, exam.title) }}
+                                      disabled={exportingId === exam.id}
+                                    >
+                                      <span className="workspace-menu-icon">↓</span>
+                                      <span>{exportingId === exam.id ? t('common.loading') : t('workspace.export')}</span>
+                                    </button>
+                                    <button
+                                      className="user-menu-item workspace-menu-item"
+                                      onClick={() => setMenuSection('move')}
+                                      disabled={movingExamId === exam.id}
+                                    >
+                                      <span className="workspace-menu-icon">▤</span>
+                                      <span>{t('workspace.moveTo')}</span>
+                                      <span className="workspace-menu-chevron">›</span>
+                                    </button>
+                                    <button
+                                      className="user-menu-item workspace-menu-item"
+                                      onClick={() => setMenuSection('share')}
+                                      disabled={sharingId === exam.id}
+                                    >
+                                      <span className="workspace-menu-icon">↗</span>
+                                      <span>
+                                        {sharingId === exam.id
+                                          ? t('common.loading')
+                                          : (exam.share_token ? t('share.shared') : t('share.share'))}
+                                      </span>
+                                      <span className="workspace-menu-chevron">›</span>
+                                    </button>
+                                    <div className="workspace-menu-divider" />
+                                    <button
+                                      className="user-menu-item workspace-menu-item workspace-menu-item-danger"
+                                      onClick={() => { closeMenu(); setDeleteConfirm(exam.id) }}
+                                    >
+                                      <span className="workspace-menu-icon">✕</span>
+                                      <span>{t('common.delete')}</span>
+                                    </button>
+                                  </>
+                                )}
+                                {menuSection === 'move' && (
+                                  <>
+                                    <button
+                                      className="user-menu-item workspace-menu-back"
+                                      onClick={() => setMenuSection('main')}
+                                    >
+                                      ‹ {t('common.back')}
+                                    </button>
+                                    <div className="workspace-menu-divider" />
+                                    {exam.collection_id !== null && (
+                                      <button
+                                        className="user-menu-item workspace-menu-item"
+                                        onClick={() => void handleMoveExam(exam.id, null)}
+                                      >
+                                        {t('workspace.removeFromCollection')}
+                                      </button>
+                                    )}
+                                    {collections.map((col) => (
+                                      col.id !== exam.collection_id && (
+                                        <button
+                                          key={col.id}
+                                          className="user-menu-item workspace-menu-item"
+                                          onClick={() => void handleMoveExam(exam.id, col.id)}
+                                        >
+                                          {col.name}
+                                        </button>
+                                      )
+                                    ))}
+                                    {collections.length === 0 && exam.collection_id === null && (
+                                      <div className="user-menu-item workspace-menu-item" style={{ color: 'var(--ink-3)', cursor: 'default' }}>
+                                        {t('workspace.collections')}: 0
+                                      </div>
+                                    )}
+                                  </>
+                                )}
+                                {menuSection === 'share' && (
+                                  <>
+                                    <button
+                                      className="user-menu-item workspace-menu-back"
+                                      onClick={() => setMenuSection('main')}
+                                    >
+                                      ‹ {t('common.back')}
+                                    </button>
+                                    <div className="workspace-menu-divider" />
+                                    {exam.share_token ? (
+                                      <>
+                                        <button
+                                          className="user-menu-item workspace-menu-item"
+                                          onClick={() => {
+                                            const url = `${window.location.origin}/share/${exam.share_token}`
+                                            void navigator.clipboard.writeText(url)
+                                            closeMenu()
+                                          }}
+                                        >
+                                          {t('share.copyLink')}
+                                        </button>
+                                        <button
+                                          className="user-menu-item workspace-menu-item workspace-menu-item-danger"
+                                          onClick={() => void handleUnshare(exam.id)}
+                                        >
+                                          {t('share.revokeLink')}
+                                        </button>
+                                      </>
+                                    ) : (
+                                      <button
+                                        className="user-menu-item workspace-menu-item"
+                                        onClick={() => void handleShare(exam.id)}
+                                      >
+                                        {sharingId === exam.id ? t('common.loading') : t('share.generateLink')}
+                                      </button>
+                                    )}
+                                  </>
+                                )}
+                              </div>
+                            </>
+                          )}
+                        </div>
+                      </>
+                    )}
+                  </div>
+                </div>
+              )
+            })}
+          </div>
+        )}
+      </div>
     </div>
   )
 }

frontend/src/components/MyResults.tsx

@@ -2,7 +2,9 @@ import { useState, useEffect, useCallback } from 'react'
 import { useNavigate } from 'react-router-dom'
 import { useTranslation } from 'react-i18next'
 import * as resultApi from '../api/resultApi'
+import * as examApi from '../api/examApi'
 import { getExamUrlId } from '../utils/slug'
+import type { Exam } from '../types'
 
 interface ResultItem {
   id: number
@@ -17,7 +19,11 @@ interface ResultItem {
   exam_id: number | null
 }
 
-export default function MyResults() {
+interface Props {
+  onLoadExam: (exam: Exam, saveToWorkspace?: boolean, examId?: number | null) => void
+}
+
+export default function MyResults({ onLoadExam }: Props) {
   const { t } = useTranslation()
   const navigate = useNavigate()
   const [results, setResults] = useState<ResultItem[]>([])
@@ -25,6 +31,7 @@ export default function MyResults() {
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState<string | null>(null)
   const [deleteConfirm, setDeleteConfirm] = useState<number | null>(null)
+  const [retakingId, setRetakingId] = useState<number | null>(null)
 
   const loadResults = useCallback(async () => {
     setLoading(true)
@@ -54,6 +61,18 @@ export default function MyResults() {
     }
   }
 
+  const retakeExam = async (item: ResultItem) => {
+    if (!item.exam_id) return
+    setRetakingId(item.id)
+    try {
+      const exam = await examApi.getExam(item.exam_id)
+      onLoadExam(exam, false, item.exam_id)
+    } catch (e) {
+      setError((e as Error).message)
+      setRetakingId(null)
+    }
+  }
+
   const reviewResult = async (item: ResultItem) => {
     try {
       const data = await resultApi.getResult(item.id)
@@ -66,6 +85,7 @@ export default function MyResults() {
         ...(state || {}),
         completedAt: typeof completedAt === 'number' ? completedAt * 1000 : Date.now(),
       }))
+      localStorage.setItem('brainwave.review.resultId', String(item.id))
       navigate(`/review/${getExamUrlId(data.exam as unknown as { title: string; id?: string })}`)
     } catch (e) {
       setError((e as Error).message)
@@ -129,8 +149,16 @@ export default function MyResults() {
                 </div>
                 <div className="workspace-card-actions" style={{ gap: 8 }}>
                   <div className={`score-pill ${passed ? 'pass' : 'fail'}`}>{pct}%</div>
+                  <button
+                    className="btn btn-primary btn-sm"
+                    onClick={() => void retakeExam(r)}
+                    disabled={retakingId === r.id || !r.exam_id}
+                    title={r.exam_id ? undefined : t('results.cantRetake')}
+                  >
+                    {retakingId === r.id ? t('common.loading') : t('results.retakeExam')}
+                  </button>
                   <button className="btn btn-sm" onClick={() => void reviewResult(r)}>
-                    {t('common.edit')}
+                    {t('results.review')}
                   </button>
                   {deleteConfirm === r.id ? (
                     <div className="workspace-delete-confirm">

frontend/src/components/Overview.tsx

@@ -0,0 +1,289 @@
+import { useState, useRef, useEffect } from 'react'
+import { useNavigate } from 'react-router-dom'
+import { useTranslation } from 'react-i18next'
+import { useAuth } from '../contexts/AuthContext'
+import * as resultApi from '../api/resultApi'
+import * as examApi from '../api/examApi'
+import { loadState } from '../utils/storage'
+import { validateExam, parseExam } from '../utils/validation'
+import type { Exam } from '../types'
+import StudyCoach from './StudyCoach'
+
+interface Props {
+  examCount: number
+  resultCount: number
+  recentResults: resultApi.ResultListItem[]
+  onLoadExam: (exam: Exam, saveToWorkspace?: boolean, examId?: number | null) => void
+}
+
+export default function Overview({ examCount, resultCount, recentResults, onLoadExam }: Props) {
+  const { t } = useTranslation()
+  const navigate = useNavigate()
+  const { user } = useAuth()
+  const [dragOver, setDragOver] = useState(false)
+  const [uploadErr, setUploadErr] = useState<string | null>(null)
+  const fileRef = useRef<HTMLInputElement>(null)
+  const [trends, setTrends] = useState<resultApi.ScoreTrend[]>([])
+  const [trendsLoading, setTrendsLoading] = useState(true)
+
+  useEffect(() => {
+    resultApi.getScoreTrends()
+      .then((data) => setTrends(data))
+      .catch(() => {/* ignore */ })
+      .finally(() => setTrendsLoading(false))
+  }, [])
+
+  const handleFile = async (file: File) => {
+    setUploadErr(null)
+    try {
+      const text = await file.text()
+      const data = JSON.parse(text) as unknown
+      const msg = validateExam(data)
+      if (msg) throw new Error(msg)
+      onLoadExam(parseExam(data), true)
+    } catch (e) {
+      setUploadErr(t('landing.loadError', { message: (e as Error).message }))
+    }
+  }
+
+  const handleRetakeWeakest = async (examId: number) => {
+    try {
+      const exam = await examApi.getExam(examId)
+      onLoadExam(exam, false, examId)
+    } catch {
+      setUploadErr(t('landing.loadError', { message: 'Could not load exam' }))
+    }
+  }
+
+  const resumable = loadState()
+  const totalQuestions = recentResults.reduce((sum, r) => sum + (r.graded_count || 0), 0)
+  const avgScore = recentResults.length > 0
+    ? Math.round(recentResults.reduce((sum, r) => sum + (r.total_points ? (r.score_points / r.total_points) * 100 : 0), 0) / recentResults.length)
+    : 0
+
+  // SVG chart dimensions
+  const margin = { top: 10, right: 20, bottom: 30, left: 40 }
+  const viewW = 520
+  const viewH = 200
+  const cw = viewW - margin.left - margin.right
+  const ch = viewH - margin.top - margin.bottom
+
+  const chartData = trends.slice(-20)
+  const hasChartData = chartData.length >= 2
+
+  const xMin = chartData.length ? chartData[0].completed_at : 0
+  const xMax = chartData.length ? chartData[chartData.length - 1].completed_at : 0
+  const xRange = xMax - xMin || 1
+
+  const xScale = (v: number) => margin.left + ((v - xMin) / xRange) * cw
+  const yScale = (v: number) => margin.top + ch - (v / 100) * ch
+
+  const linePoints = chartData.map((d, i) => {
+    const x = xScale(d.completed_at)
+    const y = yScale(d.score_pct)
+    return `${i === 0 ? 'M' : 'L'} ${x} ${y}`
+  }).join(' ')
+
+  const gridLines = [0, 25, 50, 75, 100].map((pct) => ({
+    y: yScale(pct),
+    label: `${pct}%`,
+  }))
+
+  const xLabelIndices = [...new Set([0, Math.floor(chartData.length / 2), chartData.length - 1])]
+
+  return (
+    <div className="workspace-section fade-in">
+      {/* Dashboard Stats */}
+      <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fit, minmax(140px, 1fr))', gap: 12, marginBottom: 24 }}>
+        <div className="workspace-card" style={{ padding: 16, textAlign: 'center' }}>
+          <div className="mono" style={{ fontSize: 24, fontWeight: 700 }}>{examCount}</div>
+          <div style={{ fontSize: 12, color: 'var(--ink-3)', marginTop: 4 }}>{t('workspace.myExams')}</div>
+        </div>
+        <div className="workspace-card" style={{ padding: 16, textAlign: 'center' }}>
+          <div className="mono" style={{ fontSize: 24, fontWeight: 700 }}>{resultCount}</div>
+          <div style={{ fontSize: 12, color: 'var(--ink-3)', marginTop: 4 }}>{t('workspace.totalAttempts')}</div>
+        </div>
+        <div className="workspace-card" style={{ padding: 16, textAlign: 'center' }}>
+          <div className="mono" style={{ fontSize: 24, fontWeight: 700 }}>{avgScore}%</div>
+          <div style={{ fontSize: 12, color: 'var(--ink-3)', marginTop: 4 }}>{t('workspace.avgScore')}</div>
+        </div>
+        <div className="workspace-card" style={{ padding: 16, textAlign: 'center' }}>
+          <div className="mono" style={{ fontSize: 24, fontWeight: 700 }}>{totalQuestions}</div>
+          <div style={{ fontSize: 12, color: 'var(--ink-3)', marginTop: 4 }}>{t('workspace.questionsAnswered')}</div>
+        </div>
+      </div>
+
+      {/* Quick Actions */}
+      <div style={{ display: 'flex', gap: 12, marginBottom: 24, flexWrap: 'wrap' }}>
+        <button
+          type="button"
+          className={`dropzone${dragOver ? ' drag-over' : ''}`}
+          style={{ flex: 1, minWidth: 220, padding: 16 }}
+          onClick={() => fileRef.current?.click()}
+          onDragOver={(e) => { e.preventDefault(); setDragOver(true) }}
+          onDragLeave={() => setDragOver(false)}
+          onDrop={(e) => {
+            e.preventDefault(); setDragOver(false)
+            const f = e.dataTransfer.files?.[0]
+            if (f) void handleFile(f)
+          }}
+        >
+          <div className="dropzone-icon" style={{ marginBottom: 6 }}>
+            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <path d="M12 3v12M7 8l5-5 5 5M5 21h14" />
+            </svg>
+          </div>
+          <div style={{ fontSize: 13, fontWeight: 500 }}>{t('workspace.uploadExam')}</div>
+          <div style={{ fontSize: 11, color: 'var(--ink-3)', marginTop: 2 }}>{t('workspace.uploadDropzone')}</div>
+          <input
+            ref={fileRef}
+            type="file"
+            accept="application/json,.json"
+            style={{ display: 'none' }}
+            onChange={(e) => { const f = e.target.files?.[0]; if (f) void handleFile(f) }}
+          />
+        </button>
+
+        <button
+          className="workspace-card"
+          style={{ flex: 1, minWidth: 220, padding: 16, display: 'flex', flexDirection: 'column', alignItems: 'center', justifyContent: 'center', cursor: 'pointer', background: 'var(--paper-2)' }}
+          onClick={() => navigate('/exam-editor/new')}
+        >
+          <div style={{ fontSize: 20, marginBottom: 6 }}>+</div>
+          <div style={{ fontSize: 13, fontWeight: 500 }}>{t('workspace.newExam')}</div>
+          <div style={{ fontSize: 11, color: 'var(--ink-3)', marginTop: 2 }}>{t('workspace.createFirstExam')}</div>
+        </button>
+
+        {resumable && (
+          <button
+            className="workspace-card"
+            style={{ flex: 1, minWidth: 220, padding: 16, display: 'flex', flexDirection: 'column', alignItems: 'center', justifyContent: 'center', cursor: 'pointer', background: 'var(--paper-2)', borderColor: 'var(--accent)' }}
+            onClick={() => onLoadExam(resumable.exam, false, null)}
+          >
+            <div style={{ fontSize: 20, marginBottom: 6 }}>▶</div>
+            <div style={{ fontSize: 13, fontWeight: 500 }}>{t('landing.resumeTitle')}</div>
+            <div style={{ fontSize: 11, color: 'var(--ink-3)', marginTop: 2 }}>
+              {resumable.exam.title}
+            </div>
+          </button>
+        )}
+      </div>
+
+      {uploadErr && (
+        <div style={{ marginBottom: 16, padding: '10px 14px', border: '1px solid var(--wrong)', borderRadius: 8, background: 'var(--wrong-weak)', color: 'var(--wrong)', fontSize: 13 }}>
+          {uploadErr}
+        </div>
+      )}
+
+      {/* Study Coach */}
+      <StudyCoach onRetakeWeakest={handleRetakeWeakest} />
+
+      {/* Performance Trends */}
+      {hasChartData && !trendsLoading && (
+        <div className="workspace-card" style={{ marginBottom: 24 }}>
+          <div style={{ padding: '16px 20px 4px' }}>
+            <h3 style={{ margin: '0 0 12px', fontSize: 15, fontWeight: 600 }}>{t('workspace.performanceTrends')}</h3>
+            <svg viewBox={`0 0 ${viewW} ${viewH}`} style={{ width: '100%', height: 'auto', overflow: 'visible' }}>
+              {/* Grid lines */}
+              {gridLines.map((g) => (
+                <g key={g.label}>
+                  <line
+                    x1={margin.left}
+                    x2={margin.left + cw}
+                    y1={g.y}
+                    y2={g.y}
+                    stroke="var(--line-2)"
+                    strokeDasharray="2,2"
+                    strokeWidth={1}
+                  />
+                  <text x={margin.left - 6} y={g.y + 3} textAnchor="end" fontSize={10} fill="var(--ink-3)">
+                    {g.label}
+                  </text>
+                </g>
+              ))}
+              {/* Trend line */}
+              <path
+                d={linePoints}
+                fill="none"
+                stroke="var(--accent)"
+                strokeWidth={2}
+                strokeLinecap="round"
+                strokeLinejoin="round"
+              />
+              {/* Data points */}
+              {chartData.map((d, i) => {
+                const x = xScale(d.completed_at)
+                const y = yScale(d.score_pct)
+                const date = new Date(d.completed_at * 1000).toLocaleDateString(undefined, { month: 'short', day: 'numeric' })
+                return (
+                  <g key={i}>
+                    <circle
+                      cx={x}
+                      cy={y}
+                      r={4}
+                      fill="var(--accent)"
+                      stroke="var(--paper-2)"
+                      strokeWidth={2}
+                    >
+                      <title>{`${d.title} — ${d.score_pct}% (${date})`}</title>
+                    </circle>
+                  </g>
+                )
+              })}
+              {/* X-axis labels */}
+              {xLabelIndices.map((idx) => {
+                const d = chartData[idx]
+                if (!d) return null
+                const x = xScale(d.completed_at)
+                const date = new Date(d.completed_at * 1000).toLocaleDateString(undefined, { month: 'short', day: 'numeric' })
+                return (
+                  <text key={idx} x={x} y={viewH - 6} textAnchor="middle" fontSize={10} fill="var(--ink-3)">
+                    {date}
+                  </text>
+                )
+              })}
+            </svg>
+          </div>
+        </div>
+      )}
+
+      {/* Recent Results */}
+      {recentResults.length > 0 && (
+        <div style={{ marginBottom: 24 }}>
+          <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'baseline', marginBottom: 12 }}>
+            <h3 style={{ margin: 0, fontSize: 15, fontWeight: 600 }}>{t('workspace.recentResults')}</h3>
+            <button className="btn btn-ghost btn-sm" onClick={() => navigate('/workspace/results')}>
+              {t('workspace.viewAll')} →
+            </button>
+          </div>
+          <div className="workspace-list">
+            {recentResults.map((r) => {
+              const pct = r.total_points ? Math.round((r.score_points / r.total_points) * 100) : 0
+              const passed = pct >= (r.passing_score ?? 60)
+              const d = new Date(r.completed_at * 1000)
+              const dateStr = d.toLocaleDateString('en-US', { month: 'short', day: 'numeric' })
+              return (
+                <div key={r.id} className="workspace-card" style={{ display: 'flex', alignItems: 'center', gap: 12, padding: 12 }}>
+                  <div style={{ flex: 1 }}>
+                    <div style={{ fontSize: 13, fontWeight: 500 }}>{r.title}</div>
+                    <div className="muted" style={{ fontSize: 11 }}>{dateStr}</div>
+                  </div>
+                  <div className={`score-pill ${passed ? 'pass' : 'fail'}`} style={{ fontSize: 11 }}>{pct}%</div>
+                </div>
+              )
+            })}
+          </div>
+        </div>
+      )}
+
+      {!user && (
+        <div className="workspace-card" style={{ padding: 20, textAlign: 'center' }}>
+          <div style={{ fontSize: 14, marginBottom: 8 }}>{t('workspace.signInPrompt')}</div>
+          <button className="btn btn-primary" onClick={() => { /* handled by parent */ }}>
+            {t('auth.signIn')}
+          </button>
+        </div>
+      )}
+    </div>
+  )
+}

frontend/src/components/Results.tsx

@@ -1,51 +1,127 @@
 import { useState } from 'react'
 import { useTranslation } from 'react-i18next'
-import type { Exam, ExamState } from '../types'
+import type { Exam, ExamState, Question } from '../types'
 import { gradeQuestion } from '../utils/grading'
 import { formatTime } from '../utils/formatting'
 import Tex from './Tex'
 import QuestionMedia from './QuestionMedia'
 import QuestionRenderer from './questions/QuestionRenderer'
+import * as gradeApi from '../api/gradeApi'
+import * as aiApi from '../api/aiApi'
 
 interface Props {
   exam: Exam
   state: ExamState
   onRestart: () => void
   onExit: () => void
+  onRedoFailed?: () => void
   reviewOnly?: boolean
+  resultId?: number | null
 }
 
-export default function Results({ exam, state, onRestart, onExit, reviewOnly }: Props) {
-  const { t } = useTranslation()
+const AI_TYPES = new Set(['essay', 'short-answer', 'translation', 'math-input', 'match', 'order'])
+
+function isAiApplicable(q: Question): boolean {
+  return AI_TYPES.has(q.type)
+}
+
+function mapTypeForApi(q: Question): gradeApi.GradeRequest['type'] | null {
+  switch (q.type) {
+    case 'essay': return 'essay'
+    case 'short-answer': return 'short-answer'
+    case 'translation': return 'translation'
+    case 'math-input': return 'math'
+    case 'match': return 'match'
+    case 'order': return 'ordering'
+    default: return null
+  }
+}
+
+export default function Results({ exam, state, onRestart, onExit, onRedoFailed, reviewOnly, resultId }: Props) {
+  const { t, i18n } = useTranslation()
   const { answers, startedAt, completedAt } = state
   const elapsedMs = (completedAt ?? Date.now()) - startedAt
 
-  const graded = exam.questions.map((q) => ({
-    q,
-    userAnswer: answers[q.id],
-    result: gradeQuestion(q, answers[q.id]),
-  }))
+  const [aiReviews, setAiReviews] = useState<Record<string, gradeApi.GradingResult>>({})
+  const [aiLoading, setAiLoading] = useState<Record<string, boolean>>({})
+  const [aiErrors, setAiErrors] = useState<Record<string, string>>({})
+  const [acceptedGrades, setAcceptedGrades] = useState<Record<string, number>>({})
+
+  const graded = exam.questions.map((q) => {
+    const accepted = acceptedGrades[q.id]
+    const base = gradeQuestion(q, answers[q.id])
+    if (accepted != null) {
+      const pts = q.points ?? 1
+      return {
+        ...base,
+        status: (accepted >= 0.5 ? 'correct' : 'wrong') as typeof base.status,
+        correct: accepted >= 0.5,
+        points: Math.round(pts * accepted),
+      }
+    }
+    return base
+  })
 
   const totalPoints = exam.questions.reduce((a, q) => a + (q.points ?? 1), 0)
-  const scorePoints = graded.reduce((a, g) => a + g.result.points, 0)
-  const gradedCount = graded.filter((g) => g.result.status !== 'ungraded').length
-  const correctCount = graded.filter((g) => g.result.correct).length
+  const scorePoints = graded.reduce((a, g) => a + g.points, 0)
+  const gradedCount = graded.filter((g) => g.status !== 'ungraded').length
+  const correctCount = graded.filter((g) => g.correct).length
+  const failedCount = gradedCount - correctCount
   const pct = totalPoints ? Math.round((scorePoints / totalPoints) * 100) : 0
   const passing = exam.passingScore ?? 60
   const passed = pct >= passing
 
   const byCat: Record<string, { earned: number; possible: number; correct: number; total: number }> = {}
-  graded.forEach((g) => {
-    const cat = g.q.category ?? 'Uncategorized'
+  graded.forEach((g, i) => {
+    const cat = exam.questions[i].category ?? 'Uncategorized'
     if (!byCat[cat]) byCat[cat] = { earned: 0, possible: 0, correct: 0, total: 0 }
-    byCat[cat].possible += g.q.points ?? 1
-    byCat[cat].earned += g.result.points
+    byCat[cat].possible += exam.questions[i].points ?? 1
+    byCat[cat].earned += g.points
     byCat[cat].total += 1
-    if (g.result.correct) byCat[cat].correct += 1
+    if (g.correct) byCat[cat].correct += 1
   })
 
   const [openIdx, setOpenIdx] = useState<number | null>(null)
 
+  const runAiReview = async (q: Question) => {
+    const type = mapTypeForApi(q)
+    if (!type) return
+    setAiLoading((prev) => ({ ...prev, [q.id]: true }))
+    setAiErrors((prev) => { const n = { ...prev }; delete n[q.id]; return n })
+    try {
+      const result = await gradeApi.gradeQuestion({
+        type,
+        question: q as unknown as Record<string, unknown>,
+        answer: answers[q.id],
+        language: i18n.language === 'nl' ? 'nl' : 'en',
+      })
+      setAiReviews((prev) => ({ ...prev, [q.id]: result }))
+    } catch (e) {
+      setAiErrors((prev) => ({ ...prev, [q.id]: (e as Error).message }))
+    } finally {
+      setAiLoading((prev) => { const n = { ...prev }; delete n[q.id]; return n })
+    }
+  }
+
+  const acceptGrade = (qid: string, grade: number) => {
+    setAcceptedGrades((prev) => ({ ...prev, [qid]: grade }))
+  }
+
+  const keepOriginal = (qid: string) => {
+    setAcceptedGrades((prev) => { const n = { ...prev }; delete n[qid]; return n })
+    setAiReviews((prev) => { const n = { ...prev }; delete n[qid]; return n })
+  }
+
+  const statusLabel = (status: string) => {
+    switch (status) {
+      case 'correct': return t('exam.correct')
+      case 'wrong': return t('exam.notQuite')
+      case 'ungraded': return 'Ungraded'
+      case 'unanswered': return 'Unanswered'
+      default: return status
+    }
+  }
+
   return (
     <div className="results">
       <div className="results-eyebrow">
@@ -93,40 +169,101 @@ export default function Results({ exam, state, onRestart, onExit, reviewOnly }:
         </div>
       )}
 
+      {resultId != null && <TutorChatPanel resultId={resultId} />}
+
       <h2 className="review-heading">{t('results.review')}</h2>
-      {graded.map((g, i) => {
-        const promptText = g.q.prompt
+      {exam.questions.map((q, i) => {
+        const g = graded[i]
+        const promptText = q.prompt
           .replace(/\$\$([^$]+)\$\$/g, '[math]')
           .replace(/\$([^$]+)\$/g, '[math]')
+        const aiResult = aiReviews[q.id]
+        const aiBusy = aiLoading[q.id]
+        const aiErr = aiErrors[q.id]
+        const accepted = acceptedGrades[q.id]
+        const applicable = isAiApplicable(q)
+
         return (
-          <div key={g.q.id} className={`review-item${openIdx === i ? ' open' : ''}`}>
+          <div key={q.id} className={`review-item${openIdx === i ? ' open' : ''}`}>
             <div className="review-item-header" onClick={() => setOpenIdx(openIdx === i ? null : i)}>
               <span className="review-num">{String(i + 1).padStart(2, '0')}</span>
               <span className="review-title">
                 <Tex>{promptText.slice(0, 90)}</Tex>
                 {promptText.length > 90 ? '…' : ''}
               </span>
-              <span className={`review-status ${g.result.status}`}>{g.result.status}</span>
+              <span className={`review-status ${g.status}`}>
+                {statusLabel(g.status)}
+                {accepted != null && ' ✦'}
+              </span>
               <span style={{ color: 'var(--ink-4)' }}>{openIdx === i ? '−' : '+'}</span>
             </div>
             {openIdx === i && (
               <div className="review-body">
                 <div className="q-prompt" style={{ fontSize: 20, marginBottom: 20 }}>
-                  <Tex>{g.q.prompt}</Tex>
+                  <Tex markdown>{q.prompt}</Tex>
                 </div>
-                <QuestionMedia q={g.q} />
-                <QuestionRenderer key={g.q.id} q={g.q} value={g.userAnswer} onChange={() => {}} locked graded />
-                {g.q.explanation && (
-                  <div className="feedback" style={{ marginTop: 24 }}>
-                    <div className="feedback-label">{t('results.explanation')}</div>
-                    <div className="feedback-body"><Tex>{g.q.explanation}</Tex></div>
+                <QuestionMedia q={q} />
+                <QuestionRenderer key={q.id} q={q} value={answers[q.id]} onChange={() => {}} locked graded />
+
+                {applicable && !reviewOnly && (
+                  <div style={{ marginTop: 20 }}>
+                    {!aiResult && !aiBusy && (
+                      <button
+                        className="btn btn-sm"
+                        onClick={(e) => { e.stopPropagation(); void runAiReview(q) }}
+                      >
+                        {t('results.ai.button')} ▶
+                      </button>
+                    )}
+                    {aiBusy && (
+                      <span className="muted" style={{ fontSize: 13 }}>{t('common.loading')}</span>
+                    )}
+                    {aiErr && (
+                      <div style={{ marginTop: 8, padding: '8px 12px', borderRadius: 6, background: 'var(--wrong-weak)', color: 'var(--wrong)', fontSize: 13 }}>
+                        {t('results.ai.error')}: {aiErr}
+                      </div>
+                    )}
+                    {aiResult && (
+                      <div style={{ marginTop: 12, padding: 16, border: '1px solid var(--line-2)', borderRadius: 10, background: 'var(--paper-2)' }}>
+                        <div style={{ fontWeight: 600, fontSize: 14, marginBottom: 4 }}>
+                          {t('results.ai.suggestedGrade')}: {Math.round(aiResult.suggestedGrade * 100)}%
+                        </div>
+                        <div style={{ fontSize: 13, color: 'var(--ink-2)', lineHeight: 1.6, marginBottom: 12 }}>
+                          {aiResult.feedback}
+                        </div>
+                        {!!aiResult.detail && (
+                          <AiDetail detail={aiResult.detail} type={q.type} />
+                        )}
+                        <div style={{ display: 'flex', gap: 10, marginTop: 12 }}>
+                          <button
+                            className="btn btn-primary btn-sm"
+                            onClick={(e) => { e.stopPropagation(); acceptGrade(q.id, aiResult.suggestedGrade) }}
+                          >
+                            {t('results.ai.accept')} ✓
+                          </button>
+                          <button
+                            className="btn btn-ghost btn-sm"
+                            onClick={(e) => { e.stopPropagation(); keepOriginal(q.id) }}
+                          >
+                            {t('results.ai.keepOriginal')} ✗
+                          </button>
+                        </div>
+                      </div>
+                    )}
                   </div>
                 )}
-                {g.q.rubric && (
+
+                {q.explanation && (
+                  <div className="feedback" style={{ marginTop: 24 }}>
+                    <div className="feedback-label">{t('results.explanation')}</div>
+                    <div className="feedback-body"><Tex>{q.explanation}</Tex></div>
+                  </div>
+                )}
+                {q.rubric && (
                   <div style={{ marginTop: 20, fontSize: 13.5 }}>
                     <div className="meta-label" style={{ marginBottom: 8 }}>{t('results.rubric')}</div>
                     <ul style={{ paddingLeft: 18, margin: 0, lineHeight: 1.7, color: 'var(--ink-2)' }}>
-                      {g.q.rubric.map((r, j) => <li key={j}><Tex>{r}</Tex></li>)}
+                      {q.rubric.map((r, j) => <li key={j}><Tex>{r}</Tex></li>)}
                     </ul>
                   </div>
                 )}
@@ -137,9 +274,215 @@ export default function Results({ exam, state, onRestart, onExit, reviewOnly }:
       })}
 
       <div style={{ marginTop: 48, display: 'flex', gap: 12 }}>
-        {!reviewOnly && <button className="btn btn-primary" onClick={onRestart}>{t('results.retakeExam')}</button>}
+        {!reviewOnly && (
+          <>
+            <button className="btn btn-primary" onClick={onRestart}>{t('results.retakeExam')}</button>
+            {onRedoFailed && failedCount > 0 && (
+              <button className="btn" onClick={onRedoFailed}>
+                {t('results.redoFailed')}
+              </button>
+            )}
+          </>
+        )}
         <button className="btn" onClick={onExit}>{t('results.backToHome')}</button>
       </div>
     </div>
   )
 }
+
+function AiDetail({ detail, type }: { detail: unknown; type: string }) {
+  const { t } = useTranslation()
+  if (!detail || typeof detail !== 'object') return null
+
+  const d = detail as Record<string, unknown>
+
+  if (type === 'essay' && Array.isArray(d.rubricBreakdown)) {
+    return (
+      <div style={{ marginTop: 8 }}>
+        <div className="meta-label" style={{ marginBottom: 6, fontSize: 12 }}>{t('results.ai.rubricBreakdown')}</div>
+        <table style={{ fontSize: 12, width: '100%', borderCollapse: 'collapse' }}>
+          <tbody>
+            {(d.rubricBreakdown as Array<{ item: string; met: boolean }>).map((r, i) => (
+              <tr key={i} style={{ borderBottom: '1px solid var(--line-1)' }}>
+                <td style={{ padding: '4px 0' }}>{r.item}</td>
+                <td style={{ textAlign: 'right', color: r.met ? 'var(--right)' : 'var(--wrong)' }}>
+                  {r.met ? '✓' : '✗'}
+                </td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      </div>
+    )
+  }
+
+  if ((type === 'ordering' || type === 'order') && Array.isArray(d.correctPositions)) {
+    return (
+      <div style={{ marginTop: 8, fontSize: 12, color: 'var(--ink-2)' }}>
+        {t('results.ai.suggestedGrade')}: {(d.correctPositions as number[]).length} / {Number(d.totalItems ?? 0)} {t('results.correct').toLowerCase()}
+      </div>
+    )
+  }
+
+  if (type === 'match' && (Array.isArray(d.correctPairs) || Array.isArray(d.incorrectPairs))) {
+    return (
+      <div style={{ marginTop: 8, fontSize: 12 }}>
+        {Array.isArray(d.correctPairs) && (d.correctPairs as string[]).length > 0 && (
+          <div style={{ color: 'var(--right)', marginBottom: 4 }}>
+            ✓ {(d.correctPairs as string[]).join(', ')}
+          </div>
+        )}
+        {Array.isArray(d.incorrectPairs) && (d.incorrectPairs as string[]).length > 0 && (
+          <div style={{ color: 'var(--wrong)' }}>
+            ✗ {(d.incorrectPairs as string[]).join(', ')}
+          </div>
+        )}
+      </div>
+    )
+  }
+
+  if (type === 'math-input' && typeof d.equivalent === 'boolean') {
+    return (
+      <div style={{ marginTop: 8, fontSize: 12, color: 'var(--ink-2)' }}>
+        {d.explanation as string}
+      </div>
+    )
+  }
+
+  if (type === 'translation' && (typeof d.accuracy === 'number' || typeof d.fluency === 'number')) {
+    return (
+      <div style={{ marginTop: 8, fontSize: 12, color: 'var(--ink-2)' }}>
+        Accuracy: {Math.round((d.accuracy as number) * 100)}% · Fluency: {Math.round((d.fluency as number) * 100)}%
+        {!!d.notes && <div style={{ marginTop: 4 }}>{d.notes as string}</div>}
+      </div>
+    )
+  }
+
+  if (type === 'short-answer' && d.matchedForm != null) {
+    return (
+      <div style={{ marginTop: 8, fontSize: 12, color: 'var(--ink-2)' }}>
+        {d.reason as string}
+      </div>
+    )
+  }
+
+  return null
+}
+
+function TutorChatPanel({ resultId }: { resultId: number }) {
+  const { t, i18n } = useTranslation()
+  const [open, setOpen] = useState(false)
+  const [messages, setMessages] = useState<aiApi.TutorChatMessage[]>([])
+  const [input, setInput] = useState('')
+  const [busy, setBusy] = useState(false)
+  const [err, setErr] = useState<string | null>(null)
+
+  const send = async () => {
+    const text = input.trim()
+    if (!text || busy) return
+    const next: aiApi.TutorChatMessage[] = [...messages, { role: 'user', content: text }]
+    setMessages(next)
+    setInput('')
+    setBusy(true)
+    setErr(null)
+    try {
+      const res = await aiApi.tutorChat({
+        resultId,
+        messages: next,
+        language: i18n.language || 'en',
+      })
+      setMessages((prev) => [...prev, { role: 'assistant', content: res.reply }])
+    } catch (e) {
+      setErr((e as Error).message)
+      setMessages((prev) => prev.slice(0, -1))
+      setInput(text)
+    } finally {
+      setBusy(false)
+    }
+  }
+
+  return (
+    <div style={{ margin: '24px 0', border: '1px solid var(--line-2)', borderRadius: 10, background: 'var(--paper-2)' }}>
+      <button
+        onClick={() => setOpen((v) => !v)}
+        style={{
+          width: '100%',
+          background: 'none',
+          border: 'none',
+          padding: '14px 16px',
+          fontSize: 14,
+          fontWeight: 600,
+          textAlign: 'left',
+          cursor: 'pointer',
+          color: 'var(--ink-1)',
+          display: 'flex',
+          alignItems: 'center',
+          justifyContent: 'space-between',
+        }}
+      >
+        <span>{t('results.tutor.title')}</span>
+        <span style={{ color: 'var(--ink-4)' }}>{open ? '−' : '+'}</span>
+      </button>
+      {open && (
+        <div style={{ padding: '0 16px 16px' }}>
+          <div style={{ fontSize: 12, color: 'var(--ink-3)', marginBottom: 10 }}>
+            {t('results.tutor.subtitle')}
+          </div>
+          {messages.length === 0 && (
+            <div style={{ fontSize: 12, color: 'var(--ink-4)', marginBottom: 10, fontStyle: 'italic' }}>
+              {t('results.tutor.placeholder')}
+            </div>
+          )}
+          <div style={{ display: 'flex', flexDirection: 'column', gap: 8, marginBottom: 10 }}>
+            {messages.map((m, i) => (
+              <div
+                key={i}
+                style={{
+                  alignSelf: m.role === 'user' ? 'flex-end' : 'flex-start',
+                  maxWidth: '85%',
+                  padding: '8px 12px',
+                  borderRadius: 8,
+                  background: m.role === 'user' ? 'var(--accent-weak, var(--paper))' : 'var(--paper)',
+                  border: '1px solid var(--line-1)',
+                  fontSize: 13,
+                  lineHeight: 1.5,
+                  whiteSpace: 'pre-wrap',
+                }}
+              >
+                {m.content}
+              </div>
+            ))}
+          </div>
+          {err && (
+            <div style={{ marginBottom: 8, padding: '6px 10px', borderRadius: 6, background: 'var(--wrong-weak)', color: 'var(--wrong)', fontSize: 12 }}>
+              {err}
+            </div>
+          )}
+          <div style={{ display: 'flex', gap: 8 }}>
+            <input
+              className="input"
+              value={input}
+              onChange={(e) => setInput(e.target.value)}
+              onKeyDown={(e) => {
+                if (e.key === 'Enter' && !e.shiftKey) {
+                  e.preventDefault()
+                  void send()
+                }
+              }}
+              placeholder={t('results.tutor.inputPlaceholder')}
+              disabled={busy}
+              style={{ flex: 1, fontSize: 13 }}
+            />
+            <button
+              className="btn btn-primary btn-sm"
+              onClick={() => void send()}
+              disabled={busy || !input.trim()}
+            >
+              {busy ? t('common.loading') : t('results.tutor.send')}
+            </button>
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}

frontend/src/components/Settings.tsx

@@ -25,6 +25,54 @@ function Seg<K extends string>({ value, options, onChange }: {
   )
 }
 
+function formatBytes(bytes: number): string {
+  if (bytes === 0) return '0 B'
+  const k = 1024
+  const sizes = ['B', 'KB', 'MB', 'GB']
+  const i = Math.floor(Math.log(bytes) / Math.log(k))
+  return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i]
+}
+
+function StoragePreview() {
+  const { t } = useTranslation()
+  const { user } = useAuth()
+  const used = user?.usedBytes ?? 0
+  const quota = user?.storageQuotaBytes ?? 1073741824
+  const percent = user?.usedPercent ?? 0
+
+  let barColor = 'var(--accent)'
+  let warningText: string | null = null
+  if (percent >= 95) {
+    barColor = 'var(--wrong)'
+    warningText = t('workspace.storageWarningCritical')
+  } else if (percent >= 80) {
+    barColor = 'var(--warn)'
+    warningText = t('workspace.storageWarningHigh')
+  }
+
+  return (
+    <div className="storage-overview">
+      <div className="storage-bar-track">
+        <div
+          className="storage-bar-fill"
+          style={{ width: `${Math.min(percent, 100)}%`, backgroundColor: barColor }}
+        />
+      </div>
+      <div className="storage-stats">
+        <span className="storage-used">{formatBytes(used)}</span>
+        <span className="storage-of"> {t('workspace.storageOf')} </span>
+        <span className="storage-total">{formatBytes(quota)}</span>
+        <span className="storage-percent"> ({percent}%)</span>
+      </div>
+      {warningText && (
+        <div className={`workspace-alert ${percent >= 95 ? 'workspace-alert-error' : 'workspace-alert-warning'}`}>
+          {warningText}
+        </div>
+      )}
+    </div>
+  )
+}
+
 export default function Settings() {
   const { t, i18n } = useTranslation()
   const { user, refreshUser } = useAuth()
@@ -288,6 +336,15 @@ export default function Settings() {
           </div>
         </div>
       </div>
+
+      <div className="workspace-panel">
+        <div className="workspace-panel-header">
+          <h3>{t('workspace.storage')}</h3>
+        </div>
+        <div className="workspace-panel-body workspace-settings-form">
+          <StoragePreview />
+        </div>
+      </div>
     </div>
   )
 }

frontend/src/components/ShareView.tsx

@@ -0,0 +1,117 @@
+import { useState, useEffect } from 'react'
+import { useParams, useNavigate } from 'react-router-dom'
+import { useTranslation } from 'react-i18next'
+import { useAuth } from '../contexts/AuthContext'
+import * as examApi from '../api/examApi'
+import type { Exam } from '../types'
+
+export default function ShareView({ onLoadExam }: { onLoadExam: (exam: Exam, saveToWorkspace?: boolean, examId?: number | null) => void }) {
+  const { t } = useTranslation()
+  const { token } = useParams<{ token: string }>()
+  const navigate = useNavigate()
+  const { user } = useAuth()
+  const [loading, setLoading] = useState(true)
+  const [error, setError] = useState<string | null>(null)
+  const [data, setData] = useState<{ title: string; subtitle: string | null; questionCount: number; exam: Exam; shareMode: string } | null>(null)
+  const [cloning, setCloning] = useState(false)
+
+  useEffect(() => {
+    if (!token) {
+      setError('Invalid link')
+      setLoading(false)
+      return
+    }
+    examApi.getSharedExam(token)
+      .then((res) => {
+        setData({
+          title: res.title,
+          subtitle: res.subtitle,
+          questionCount: res.questionCount,
+          exam: res.exam as Exam,
+          shareMode: res.shareMode ?? 'clone',
+        })
+        setLoading(false)
+      })
+      .catch((e) => {
+        setError((e as Error).message)
+        setLoading(false)
+      })
+  }, [token])
+
+  const handleTake = () => {
+    if (!data) return
+    onLoadExam(data.exam, false, null)
+  }
+
+  const handleClone = async () => {
+    if (!token || !data) return
+    if (!user) {
+      navigate('/')
+      return
+    }
+    setCloning(true)
+    try {
+      await examApi.cloneSharedExam(token)
+      navigate('/workspace/exams')
+    } catch (e) {
+      setError((e as Error).message)
+      setCloning(false)
+    }
+  }
+
+  if (loading) {
+    return (
+      <div className="shell">
+        <div className="workspace-empty">{t('common.loading')}</div>
+      </div>
+    )
+  }
+
+  if (error || !data) {
+    return (
+      <div className="shell">
+        <div className="workspace-empty">
+          <div className="workspace-empty-icon">!</div>
+          <div className="workspace-empty-title">{error || 'Not found'}</div>
+          <button className="btn btn-primary" onClick={() => navigate('/')} style={{ marginTop: 16 }}>
+            {t('results.backToHome')}
+          </button>
+        </div>
+      </div>
+    )
+  }
+
+  return (
+    <div className="shell">
+      <div className="landing" style={{ maxWidth: 640, margin: '0 auto', paddingTop: 40 }}>
+        <div className="landing-eyebrow">{t('common.appName')}</div>
+        <h1 className="landing-title">{data.title}</h1>
+        {data.subtitle && <p className="landing-sub">{data.subtitle}</p>}
+
+        <div style={{ marginTop: 24, padding: 20, border: '1px solid var(--line-2)', borderRadius: 12, background: 'var(--paper-2)' }}>
+          <div style={{ fontSize: 14, marginBottom: 8 }}>
+            <span className="mono" style={{ color: 'var(--ink-3)' }}>{data.questionCount}</span> {data.questionCount === 1 ? t('common.question') : t('common.questions')}
+          </div>
+          <div style={{ display: 'flex', gap: 12, marginTop: 16 }}>
+            <button className="btn btn-primary" onClick={handleTake}>
+              {t('share.takeExam')}
+            </button>
+            {user && data.shareMode !== 'view' ? (
+              <button className="btn btn-ghost" onClick={() => void handleClone()} disabled={cloning}>
+                {cloning ? t('common.loading') : t('share.saveToWorkspace')}
+              </button>
+            ) : user ? (
+              <span className="muted" style={{ fontSize: 12, alignSelf: 'center' }}>
+                {t('workspace.shareModeView')}
+              </span>
+            ) : (
+              <button className="btn btn-ghost" onClick={() => navigate('/')}>
+                {t('auth.signIn')} →
+              </button>
+            )}
+          </div>
+        </div>
+      </div>
+    </div>
+  )
+}

frontend/src/components/SharedWithMe.tsx

@@ -0,0 +1,92 @@
+import { useState, useEffect, useCallback } from 'react'
+import { useNavigate } from 'react-router-dom'
+import { useTranslation } from 'react-i18next'
+import * as examApi from '../api/examApi'
+import type { Exam } from '../types'
+
+interface Props {
+  onLoadExam: (exam: Exam, saveToWorkspace?: boolean, examId?: number | null) => void
+}
+
+export default function SharedWithMe({ onLoadExam }: Props) {
+  const { t } = useTranslation()
+  const navigate = useNavigate()
+  const [exams, setExams] = useState<examApi.ClonedExamItem[]>([])
+  const [loading, setLoading] = useState(true)
+
+  const load = useCallback(async () => {
+    setLoading(true)
+    try {
+      const data = await examApi.listClonedExams()
+      setExams(data)
+    } catch {
+      setExams([])
+    } finally {
+      setLoading(false)
+    }
+  }, [])
+
+  useEffect(() => {
+    void load()
+  }, [load])
+
+  if (loading) {
+    return (
+      <div className="workspace-section">
+        <div className="workspace-empty" style={{ padding: 40 }}>{t('common.loading')}</div>
+      </div>
+    )
+  }
+
+  if (exams.length === 0) {
+    return (
+      <div className="workspace-section fade-in">
+        <h2 style={{ margin: '0 0 16px', fontSize: 18, fontWeight: 600 }}>{t('workspace.sharedWithMe')}</h2>
+        <div className="workspace-empty" style={{ padding: 40 }}>
+          <div className="workspace-empty-icon">
+            <svg width="40" height="40" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round">
+              <path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71" />
+              <path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71" />
+            </svg>
+          </div>
+          <div className="workspace-empty-title">{t('workspace.noSharedExams')}</div>
+          <div className="workspace-empty-desc">{t('workspace.noSharedExamsDesc')}</div>
+        </div>
+      </div>
+    )
+  }
+
+  return (
+    <div className="workspace-section fade-in">
+      <h2 style={{ margin: '0 0 16px', fontSize: 18, fontWeight: 600 }}>{t('workspace.sharedWithMe')}</h2>
+      <div className="workspace-list" style={{ display: 'flex', flexDirection: 'column', gap: 12 }}>
+        {exams.map((exam) => (
+          <div
+            key={exam.id}
+            className="workspace-card"
+            style={{ padding: 16, display: 'flex', alignItems: 'center', gap: 12, cursor: 'pointer' }}
+            onClick={() => {
+              void examApi.getExam(exam.id).then((e) => onLoadExam(e, false, exam.id))
+            }}
+          >
+            <div style={{ flex: 1 }}>
+              <div style={{ fontSize: 14, fontWeight: 500 }}>{exam.title}</div>
+              <div className="muted" style={{ fontSize: 12, marginTop: 2 }}>
+                {exam.question_count} {exam.question_count === 1 ? t('common.question') : t('common.questions')}
+              </div>
+            </div>
+            <button
+              className="btn btn-sm"
+              onClick={(ev) => {
+                ev.stopPropagation()
+                navigate(`/exam-editor/${exam.id}`)
+              }}
+            >
+              {t('common.edit')}
+            </button>
+          </div>
+        ))}
+      </div>
+    </div>
+  )
+}

frontend/src/components/StorageManager.tsx

@@ -0,0 +1,187 @@
+import { useState, useEffect, useCallback } from 'react'
+import { useTranslation } from 'react-i18next'
+import { useAuth } from '../contexts/AuthContext'
+import * as examApi from '../api/examApi'
+import * as resultApi from '../api/resultApi'
+
+function formatBytes(bytes: number): string {
+  if (bytes === 0) return '0 B'
+  const k = 1024
+  const sizes = ['B', 'KB', 'MB', 'GB']
+  const i = Math.floor(Math.log(bytes) / Math.log(k))
+  return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i]
+}
+
+export default function StorageManager() {
+  const { t } = useTranslation()
+  const { user, refreshUser } = useAuth()
+  const [exams, setExams] = useState<examApi.ExamListItem[]>([])
+  const [results, setResults] = useState<resultApi.ResultListItem[]>([])
+  const [showDetails, setShowDetails] = useState(false)
+  const [deleting, setDeleting] = useState<number | null>(null)
+
+  const loadData = useCallback(async () => {
+    try {
+      const examList = await examApi.listExams()
+      setExams(examList)
+      const resultList = await resultApi.listResults()
+      setResults(resultList.results)
+    } catch {
+      // silently ignore
+    }
+  }, [])
+
+  useEffect(() => {
+    void loadData()
+  }, [loadData])
+
+  const handleDeleteExam = useCallback(async (id: number) => {
+    if (!window.confirm(t('workspace.deleteExamConfirm'))) return
+    setDeleting(id)
+    try {
+      await examApi.deleteExam(id)
+      await loadData()
+      await refreshUser()
+    } catch {
+      // ignore
+    } finally {
+      setDeleting(null)
+    }
+  }, [loadData, refreshUser, t])
+
+  const handleDeleteResult = useCallback(async (id: number) => {
+    if (!window.confirm(t('workspace.deleteResultConfirm'))) return
+    setDeleting(id)
+    try {
+      await resultApi.deleteResult(id)
+      await loadData()
+      await refreshUser()
+    } catch {
+      // ignore
+    } finally {
+      setDeleting(null)
+    }
+  }, [loadData, refreshUser, t])
+
+  const used = user?.usedBytes ?? 0
+  const quota = user?.storageQuotaBytes ?? 1073741824
+  const percent = user?.usedPercent ?? 0
+
+  let barColor = 'var(--accent)'
+  let warningText: string | null = null
+  if (percent >= 95) {
+    barColor = 'var(--wrong)'
+    warningText = t('workspace.storageWarningCritical')
+  } else if (percent >= 80) {
+    barColor = 'var(--warn)'
+    warningText = t('workspace.storageWarningHigh')
+  }
+
+  return (
+    <div className="workspace-section fade-in">
+      <div className="workspace-section-header">
+        <div>
+          <div className="workspace-section-eyebrow">{t('workspace.myWorkspace')}</div>
+          <h2 className="workspace-section-title">{t('workspace.storage')}</h2>
+        </div>
+      </div>
+
+      <div className="workspace-panel">
+        <div className="workspace-panel-header">
+          <h3>{t('workspace.storageUsage')}</h3>
+        </div>
+        <div className="workspace-panel-body workspace-settings-form">
+          <div className="storage-overview">
+            <div className="storage-bar-track">
+              <div
+                className="storage-bar-fill"
+                style={{ width: `${Math.min(percent, 100)}%`, backgroundColor: barColor }}
+              />
+            </div>
+            <div className="storage-stats">
+              <span className="storage-used">{formatBytes(used)}</span>
+              <span className="storage-of"> {t('workspace.storageOf')} </span>
+              <span className="storage-total">{formatBytes(quota)}</span>
+              <span className="storage-percent"> ({percent}%)</span>
+            </div>
+            {warningText && (
+              <div className={`workspace-alert ${percent >= 95 ? 'workspace-alert-error' : 'workspace-alert-warning'}`}>
+                {warningText}
+              </div>
+            )}
+          </div>
+
+          <div className="storage-breakdown">
+            <div className="storage-breakdown-row">
+              <span>{t('workspace.storageExams')}</span>
+              <span>{exams.length}</span>
+            </div>
+            <div className="storage-breakdown-row">
+              <span>{t('workspace.storageResults')}</span>
+              <span>{results.length}</span>
+            </div>
+          </div>
+
+          <div className="workspace-settings-footer">
+            <button
+              className="btn btn-ghost"
+              onClick={() => setShowDetails((v) => !v)}
+            >
+              {showDetails ? t('workspace.hideDetails') : t('workspace.showDetails')}
+            </button>
+          </div>
+        </div>
+      </div>
+
+      {showDetails && (
+        <div className="workspace-panel">
+          <div className="workspace-panel-header">
+            <h3>{t('workspace.storageDetails')}</h3>
+          </div>
+          <div className="workspace-panel-body">
+            {exams.length === 0 && results.length === 0 ? (
+              <p className="text-muted">{t('workspace.noStorageItems')}</p>
+            ) : (
+              <div className="storage-detail-list">
+                {exams.map((exam) => (
+                  <div key={`exam-${exam.id}`} className="storage-detail-item">
+                    <div className="storage-detail-info">
+                      <span className="storage-detail-type">{t('workspace.exam')}</span>
+                      <span className="storage-detail-title">{exam.title}</span>
+                    </div>
+                    <div className="storage-detail-actions">
+                      <button
+                        className="btn btn-danger btn-sm"
+                        onClick={() => handleDeleteExam(exam.id)}
+                        disabled={deleting === exam.id}
+                      >
+                        {deleting === exam.id ? t('common.loading') : t('common.delete')}
+                      </button>
+                    </div>
+                  </div>
+                ))}
+                {results.map((result) => (
+                  <div key={`result-${result.id}`} className="storage-detail-item">
+                    <div className="storage-detail-info">
+                      <span className="storage-detail-type">{t('workspace.result')}</span>
+                      <span className="storage-detail-title">{result.title}</span>
+                    </div>
+                    <div className="storage-detail-actions">
+                      <button
+                        className="btn btn-danger btn-sm"
+                        onClick={() => handleDeleteResult(result.id)}
+                        disabled={deleting === result.id}
+                      >
+                        {deleting === result.id ? t('common.loading') : t('common.delete')}
+                      </button>
+                    </div>
+                  </div>
+                ))}
+              </div>
+            )}
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}

frontend/src/components/StudyCoach.tsx

@@ -0,0 +1,106 @@
+import { useState, useEffect } from 'react'
+import { useTranslation } from 'react-i18next'
+import { useNavigate } from 'react-router-dom'
+import * as resultApi from '../api/resultApi'
+
+interface Props {
+  onRetakeWeakest?: (examId: number) => void
+}
+
+export default function StudyCoach({ onRetakeWeakest }: Props) {
+  const { t } = useTranslation()
+  const navigate = useNavigate()
+  const [data, setData] = useState<resultApi.StudyCoachResult | null>(null)
+  const [loading, setLoading] = useState(true)
+
+  useEffect(() => {
+    resultApi.analyzeResults()
+      .then((res) => setData(res))
+      .catch(() => {/* ignore */})
+      .finally(() => setLoading(false))
+  }, [])
+
+  if (loading) {
+    return (
+      <div className="workspace-card" style={{ marginBottom: 24 }}>
+        <div className="workspace-empty" style={{ padding: 24 }}>{t('common.loading')}</div>
+      </div>
+    )
+  }
+
+  if (!data || (data.weakAreas.length === 0 && data.studyTips.length === 0 && !data.weakestExamId)) {
+    return null
+  }
+
+  return (
+    <div className="workspace-card" style={{ marginBottom: 24, borderLeft: '3px solid var(--accent)' }}>
+      <div style={{ padding: 20 }}>
+        <div style={{ display: 'flex', alignItems: 'center', gap: 8, marginBottom: 12 }}>
+          <span style={{ fontSize: 18 }}>🤖</span>
+          <h3 style={{ margin: 0, fontSize: 15, fontWeight: 600 }}>{t('workspace.studyCoachTitle')}</h3>
+          {data.streakDays > 0 && (
+            <span className="mono" style={{ fontSize: 12, color: 'var(--ink-3)', marginLeft: 'auto' }}>
+              🔥 {data.streakDays} {data.streakDays === 1 ? t('workspace.streakDay') : t('workspace.streakDays')}
+            </span>
+          )}
+        </div>
+
+        {data.weakestExamId && onRetakeWeakest && (
+          <div style={{ marginBottom: 12 }}>
+            <button
+              className="btn btn-sm"
+              style={{ background: 'var(--wrong)', color: 'white', borderColor: 'var(--wrong)' }}
+              onClick={() => onRetakeWeakest(data.weakestExamId!)}
+            >
+              🔄 {t('workspace.retakeWeakest')}
+            </button>
+          </div>
+        )}
+
+        {data.weakAreas.length > 0 && (
+          <div style={{ marginBottom: 12 }}>
+            {data.weakAreas.slice(0, 3).map((area) => (
+              <div key={area.category} style={{ display: 'flex', alignItems: 'center', gap: 10, marginBottom: 8 }}>
+                <div style={{ flex: 1, height: 6, background: 'var(--line-2)', borderRadius: 3, overflow: 'hidden' }}>
+                  <div
+                    style={{
+                      width: `${area.avgScore}%`,
+                      height: '100%',
+                      background: area.avgScore >= 60 ? 'var(--ok)' : 'var(--wrong)',
+                      borderRadius: 3,
+                    }}
+                  />
+                </div>
+                <span className="mono" style={{ fontSize: 12, minWidth: 40, textAlign: 'right' }}>
+                  {area.avgScore}%
+                </span>
+                <span style={{ fontSize: 13, minWidth: 120 }}>{area.category}</span>
+              </div>
+            ))}
+          </div>
+        )}
+
+        {data.studyTips.length > 0 && (
+          <div style={{ padding: 12, background: 'var(--paper)', borderRadius: 8 }}>
+            <div className="mono" style={{ fontSize: 10, textTransform: 'uppercase', letterSpacing: '0.1em', color: 'var(--ink-3)', marginBottom: 8 }}>
+              {t('workspace.studyTips')}
+            </div>
+            <ul style={{ margin: 0, paddingLeft: 18, fontSize: 13, lineHeight: 1.7, color: 'var(--ink-2)' }}>
+              {data.studyTips.map((tip, i) => (
+                <li key={i}>{tip}</li>
+              ))}
+            </ul>
+          </div>
+        )}
+
+        <button
+          className="btn btn-ghost btn-sm"
+          style={{ marginTop: 12 }}
+          onClick={() => navigate('/workspace/results')}
+        >
+          {t('workspace.viewAllResults')} →
+        </button>
+      </div>
+    </div>
+  )
+}

frontend/src/components/Tex.tsx

@@ -1,16 +1,22 @@
 import type React from 'react'
 import { renderLatex } from '../utils/latex'
+import { renderMarkdown } from '../utils/markdown'
 
 interface TexProps {
   children?: string | null
   tag?: keyof React.JSX.IntrinsicElements
   className?: string
   style?: React.CSSProperties
+  markdown?: boolean
 }
 
 // Safe: renderLatex only produces KaTeX-controlled HTML + HTML-escaped plain text.
-export default function Tex({ children, tag = 'span', className, style }: Readonly<TexProps>) {
+// When markdown is true, uses renderMarkdown which applies marked + KaTeX + DOMPurify.
+export default function Tex({ children, tag = 'span', className, style, markdown }: Readonly<TexProps>) {
   const Tag = tag as React.ElementType
-  const html = String(children ?? '').split('\n').map(renderLatex).join('<br/>')
+  const text = String(children ?? '')
+  const html = markdown
+    ? renderMarkdown(text)
+    : text.split('\n').map(renderLatex).join('<br/>')
   return <Tag className={className} style={style} dangerouslySetInnerHTML={{ __html: html }} />
 }

frontend/src/components/Workspace.tsx

@@ -1,19 +1,36 @@
 import { useState, useEffect, useCallback } from 'react'
+import type { ReactNode } from 'react'
 import { useNavigate, useParams, Navigate } from 'react-router-dom'
 import { useTranslation } from 'react-i18next'
 import { useAuth } from '../contexts/AuthContext'
 import * as examApi from '../api/examApi'
 import * as resultApi from '../api/resultApi'
+import { downloadInstructions } from '../utils/instructions'
 import type { Exam } from '../types'
 import MyExams from './MyExams'
 import MyResults from './MyResults'
 import Settings from './Settings'
+import StorageManager from './StorageManager'
+import Overview from './Overview'
+import SharedWithMe from './SharedWithMe'
 
-type TabKey = 'exams' | 'results' | 'settings'
+type TabKey = 'overview' | 'exams' | 'shared' | 'results' | 'storage' | 'settings'
 
-const TAB_KEYS: { key: TabKey; labelKey: string; icon: string }[] = [
+const TAB_KEYS: { key: TabKey; labelKey: string; icon: ReactNode }[] = [
+  { key: 'overview', labelKey: 'workspace.overview', icon: '◈' },
   { key: 'exams', labelKey: 'workspace.myExams', icon: '◇' },
+  {
+    key: 'shared',
+    labelKey: 'workspace.sharedWithMe',
+    icon: (
+      <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+        <path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71" />
+        <path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71" />
+      </svg>
+    ),
+  },
   { key: 'results', labelKey: 'workspace.results', icon: '✦' },
+  { key: 'storage', labelKey: 'workspace.storage', icon: '◉' },
   { key: 'settings', labelKey: 'workspace.settings', icon: '⚙' },
 ]
 
@@ -26,9 +43,10 @@ export default function Workspace({ onLoadExam }: Props) {
   const { user, loading: authLoading } = useAuth()
   const navigate = useNavigate()
   const { tab } = useParams<{ tab: string }>()
-  const activeTab = (tab as TabKey) ?? 'exams'
+  const activeTab = (tab as TabKey) ?? 'overview'
   const [examCount, setExamCount] = useState(0)
   const [resultCount, setResultCount] = useState(0)
+  const [recentResults, setRecentResults] = useState<resultApi.ResultListItem[]>([])
 
   const loadCounts = useCallback(async () => {
     try {
@@ -36,6 +54,7 @@ export default function Workspace({ onLoadExam }: Props) {
       setExamCount(exams.length)
       const results = await resultApi.listResults()
       setResultCount(results.total)
+      setRecentResults(results.results.slice(0, 5))
     } catch {
       // silently ignore
     }
@@ -45,11 +64,11 @@ export default function Workspace({ onLoadExam }: Props) {
     if (user) void loadCounts()
   }, [user, loadCounts])
 
+  const setTab = (key: TabKey) => navigate(`/workspace/${key}`)
+
   if (authLoading) return null
   if (!user) return <Navigate to="/" replace />
 
-  const setTab = (key: TabKey) => navigate(`/workspace/${key}`)
-
   return (
     <div className="workspace-shell">
       <aside className="workspace-sidebar">
@@ -58,7 +77,6 @@ export default function Workspace({ onLoadExam }: Props) {
             {user.displayName.charAt(0).toUpperCase()}
           </div>
           <div className="workspace-name">{user.displayName}</div>
-          <div className="workspace-email">{user.email}</div>
         </div>
 
         <nav className="workspace-nav">
@@ -79,11 +97,35 @@ export default function Workspace({ onLoadExam }: Props) {
             </button>
           ))}
         </nav>
+
+        <div className="workspace-sidebar-footer">
+          <button
+            type="button"
+            className="btn btn-ghost"
+            onClick={downloadInstructions}
+            title={t('workspace.downloadInstructions')}
+          >
+            <span style={{ display: 'inline-flex', alignItems: 'center', justifyContent: 'center', width: 18, height: 18, border: '1.5px solid currentColor', borderRadius: 5, fontSize: 12, lineHeight: 1, flexShrink: 0 }}>
+              {t('landing.downloadInstructionsIcon')}
+            </span>
+            {t('workspace.downloadInstructions')}
+          </button>
+        </div>
       </aside>
 
       <main className="workspace-main">
+        {activeTab === 'overview' && (
+          <Overview
+            examCount={examCount}
+            resultCount={resultCount}
+            recentResults={recentResults}
+            onLoadExam={onLoadExam}
+          />
+        )}
         {activeTab === 'exams' && <MyExams onLoadExam={onLoadExam} />}
-        {activeTab === 'results' && <MyResults />}
+        {activeTab === 'shared' && <SharedWithMe onLoadExam={onLoadExam} />}
+        {activeTab === 'results' && <MyResults onLoadExam={onLoadExam} />}
+        {activeTab === 'storage' && <StorageManager />}
         {activeTab === 'settings' && <Settings />}
       </main>
     </div>

frontend/src/components/questions/CodeSubmission.tsx

@@ -0,0 +1,56 @@
+import type { Question } from '../../types'
+
+interface CodeValue {
+  code?: string
+  selfGrade?: number
+  [key: string]: unknown
+}
+
+interface Props {
+  q: Question
+  value: CodeValue | string | null | undefined
+  onChange: (val: CodeValue) => void
+  locked?: boolean
+}
+
+export default function CodeSubmission({ q, value, onChange, locked }: Props) {
+  const cfg = q.codeConfig
+  const language = cfg?.language ?? 'text'
+  const starterCode = cfg?.starterCode ?? ''
+
+  const val = typeof value === 'string' ? { code: value } : ((value as CodeValue) ?? {})
+  const code = val.code ?? starterCode
+
+  return (
+    <div className="code-submission-wrap" style={{ maxWidth: 720 }}>
+      <div className="code-submission-bar">
+        <span className="code-lang-badge">{language}</span>
+        {cfg?.starterCode && (
+          <button
+            className="btn btn-ghost btn-sm"
+            onClick={() => onChange({ ...val, code: cfg.starterCode })}
+            disabled={locked}
+            type="button"
+          >
+            Reset code
+          </button>
+        )}
+      </div>
+      <textarea
+        className="code-submission-area"
+        value={code}
+        onChange={(e) => onChange({ ...val, code: e.target.value })}
+        placeholder="Write your code here…"
+        disabled={locked}
+        rows={12}
+        spellCheck={false}
+        autoComplete="off"
+        autoCapitalize="off"
+        autoCorrect="off"
+      />
+      <div className="code-submission-hint mono faint">
+        Self-graded · see rubric on review
+      </div>
+    </div>
+  )
+}

frontend/src/components/questions/Dictation.tsx

@@ -0,0 +1,77 @@
+import { useRef, useState } from 'react'
+import type { Question } from '../../types'
+
+interface Props {
+  q: Question
+  value: string | null | undefined
+  onChange: (val: string) => void
+  locked?: boolean
+}
+
+export default function Dictation({ q, value = '', onChange, locked }: Props) {
+  const audioRef = useRef<HTMLAudioElement>(null)
+  const [playing, setPlaying] = useState(false)
+  const [playbackRate, setPlaybackRate] = useState(1)
+
+  const togglePlay = () => {
+    if (!audioRef.current) return
+    if (playing) {
+      audioRef.current.pause()
+    } else {
+      audioRef.current.playbackRate = playbackRate
+      audioRef.current.play()
+    }
+  }
+
+  return (
+    <div className="answer-input-wrap">
+      {q.audio?.src && (
+        <div className="dictation-audio-wrap">
+          <audio
+            ref={audioRef}
+            src={q.audio.src}
+            onPlay={() => setPlaying(true)}
+            onPause={() => setPlaying(false)}
+            onEnded={() => setPlaying(false)}
+            preload="metadata"
+          />
+          <button
+            className={`btn btn-sm dictation-play-btn${playing ? ' playing' : ''}`}
+            onClick={togglePlay}
+            type="button"
+            disabled={locked}
+            aria-label={playing ? 'Pause' : 'Play'}
+          >
+            {playing ? '⏸ Pause' : '▶ Play'}
+          </button>
+          <div className="dictation-speed">
+            <label className="faint" style={{ fontSize: 11 }}>Speed</label>
+            {[0.5, 0.75, 1, 1.25, 1.5].map((rate) => (
+              <button
+                key={rate}
+                className={`btn btn-ghost btn-sm dictation-speed-btn${playbackRate === rate ? ' active' : ''}`}
+                onClick={() => {
+                  setPlaybackRate(rate)
+                  if (audioRef.current) audioRef.current.playbackRate = rate
+                }}
+                type="button"
+                disabled={locked}
+              >
+                {rate}x
+              </button>
+            ))}
+          </div>
+        </div>
+      )}
+      <input
+        className="input"
+        type="text"
+        value={value ?? ''}
+        onChange={(e) => onChange(e.target.value)}
+        placeholder="Type what you hear…"
+        disabled={locked}
+        autoComplete="off"
+      />
+    </div>
+  )
+}

frontend/src/components/questions/DropdownCompletion.tsx

@@ -0,0 +1,75 @@
+import type { Question } from '../../types'
+
+interface Props {
+  q: Question
+  value: Record<string, string> | null | undefined
+  onChange: (val: Record<string, string>) => void
+  locked?: boolean
+  graded?: boolean
+}
+
+export default function DropdownCompletion({ q, value, onChange, locked, graded }: Props) {
+  const current = value ?? {}
+  const segments = q.textSegments ?? []
+  const dropdowns = q.dropdowns ?? []
+
+  const handleChange = (id: string, optionId: string) => {
+    onChange({ ...current, [id]: optionId })
+  }
+
+  return (
+    <div className="cloze-text" style={{ lineHeight: 2.2 }}>
+      {segments.map((segment, i) => (
+        <span key={`s-${i}`}>
+          <span>{segment}</span>
+          {i < dropdowns.length && (
+            <DropdownSelect
+              dropdown={dropdowns[i]}
+              value={current[dropdowns[i].id] ?? ''}
+              onChange={(v) => handleChange(dropdowns[i].id, v)}
+              locked={locked}
+              graded={graded}
+            />
+          )}
+        </span>
+      ))}
+    </div>
+  )
+}
+
+function DropdownSelect({
+  dropdown,
+  value,
+  onChange,
+  locked,
+  graded,
+}: {
+  dropdown: { id: string; options: Array<{ id: string; text: string }>; correctOptionId: string }
+  value: string
+  onChange: (v: string) => void
+  locked?: boolean
+  graded?: boolean
+}) {
+  let cls = 'cloze-dropdown'
+  if (graded) {
+    cls += value === dropdown.correctOptionId ? ' correct' : value ? ' wrong' : ''
+  }
+
+  return (
+    <select
+      className={cls}
+      value={value}
+      onChange={(e) => onChange(e.target.value)}
+      disabled={locked}
+    >
+      <option value="" disabled>
+        —
+      </option>
+      {dropdown.options.map((opt) => (
+        <option key={opt.id} value={opt.id}>
+          {opt.text}
+        </option>
+      ))}
+    </select>
+  )
+}

frontend/src/components/questions/FillInTheBlanks.tsx

@@ -0,0 +1,76 @@
+import type { Question } from '../../types'
+
+interface Props {
+  q: Question
+  value: Record<string, string> | null | undefined
+  onChange: (val: Record<string, string>) => void
+  locked?: boolean
+  graded?: boolean
+}
+
+export default function FillInTheBlanks({ q, value, onChange, locked, graded }: Props) {
+  const current = value ?? {}
+  const blanks = q.blanks ?? []
+  const segments = q.textSegments ?? []
+
+  const handleChange = (blankId: string, text: string) => {
+    onChange({ ...current, [blankId]: text })
+  }
+
+  return (
+    <div className="cloze-text" style={{ lineHeight: 2.2 }}>
+      {segments.map((segment, i) => (
+        <span key={`s-${i}`}>
+          <span>{segment}</span>
+          {i < blanks.length && (
+            <BlankInput
+              blank={blanks[i]}
+              value={current[blanks[i].id] ?? ''}
+              onChange={(v) => handleChange(blanks[i].id, v)}
+              locked={locked}
+              graded={graded}
+            />
+          )}
+        </span>
+      ))}
+    </div>
+  )
+}
+
+function BlankInput({
+  blank,
+  value,
+  onChange,
+  locked,
+  graded,
+}: {
+  blank: { id: string; acceptedAnswers: string[] }
+  value: string
+  onChange: (v: string) => void
+  locked?: boolean
+  graded?: boolean
+}) {
+  let cls = 'cloze-blank'
+  if (graded) {
+    // Simple check: if the normalized value matches any accepted answer
+    const normalized = value.toLowerCase().trim()
+    const ok = blank.acceptedAnswers.some((a) => a.toLowerCase().trim() === normalized)
+    cls += ok ? ' correct' : ' wrong'
+  }
+
+  return (
+    <input
+      className={cls}
+      type="text"
+      value={value}
+      onChange={(e) => onChange(e.target.value)}
+      disabled={locked}
+      autoComplete="off"
+      spellCheck={false}
+      style={{
+        width: Math.max(80, (value.length + 2) * 10),
+        minWidth: 80,
+      }}
+    />
+  )
+}

frontend/src/components/questions/Flashcard.tsx

@@ -0,0 +1,73 @@
+import Tex from '../Tex'
+import type { Question } from '../../types'
+
+interface Props {
+  q: Question
+  value: { revealed?: boolean; selfGrade?: number } | null | undefined
+  onChange: (val: { revealed?: boolean; selfGrade?: number }) => void
+  locked?: boolean
+}
+
+export default function Flashcard({ q, value, onChange, locked }: Props) {
+  const { revealed = false, selfGrade } = value ?? {}
+
+  const handleReveal = () => {
+    if (locked) return
+    onChange({ ...value, revealed: true })
+  }
+
+  const handleGrade = (grade: number) => {
+    if (locked) return
+    onChange({ revealed: true, selfGrade: grade })
+  }
+
+  return (
+    <div className="flashcard-wrap">
+      <div className="flashcard-prompt">
+        <Tex markdown>{q.prompt}</Tex>
+      </div>
+
+      {!revealed ? (
+        <button
+          className="btn flashcard-reveal-btn"
+          onClick={handleReveal}
+          disabled={locked}
+          type="button"
+        >
+          Reveal Answer
+        </button>
+      ) : (
+        <>
+          <div className="flashcard-answer">
+            {q.answer as string}
+          </div>
+          {q.explanation && (
+            <div className="flashcard-explanation">
+              {q.explanation}
+            </div>
+          )}
+          {selfGrade == null ? (
+            <div className="flashcard-grade">
+              <div className="faint" style={{ fontSize: 12, marginBottom: 6 }}>How well did you know this?</div>
+              <div className="flashcard-grade-btns">
+                <button className="btn btn-sm flashcard-grade-wrong" onClick={() => handleGrade(0)} type="button">
+                  Didn't know
+                </button>
+                <button className="btn btn-sm flashcard-grade-hard" onClick={() => handleGrade(0.5)} type="button">
+                  Hard
+                </button>
+                <button className="btn btn-sm flashcard-grade-good" onClick={() => handleGrade(1)} type="button">
+                  Good
+                </button>
+              </div>
+            </div>
+          ) : (
+            <div className={`flashcard-grade-result ${selfGrade >= 0.5 ? 'correct' : 'wrong'}`}>
+              {selfGrade >= 0.5 ? '✓ Marked as known' : '✗ Marked as needs practice'}
+            </div>
+          )}
+        </>
+      )}
+    </div>
+  )
+}

frontend/src/components/questions/GrammarCorrection.tsx

@@ -0,0 +1,36 @@
+import Tex from '../Tex'
+import type { Question } from '../../types'
+
+interface Props {
+  q: Question
+  value: string | null | undefined
+  onChange: (val: string) => void
+  locked?: boolean
+  graded?: boolean
+}
+
+export default function GrammarCorrection({ q, value = '', onChange, locked, graded: _graded }: Props) {
+  const displayText = q.textToCorrect || q.prompt
+  return (
+    <div className="answer-input-wrap">
+      <div className="grammar-text-wrap">
+        <div className="grammar-label faint" style={{ fontSize: 12, marginBottom: 4 }}>
+          Sentence to correct:
+        </div>
+        <div className="grammar-sentence">
+          <Tex markdown>{displayText}</Tex>
+        </div>
+      </div>
+      <input
+        className="input"
+        type="text"
+        value={value ?? ''}
+        onChange={(e) => onChange(e.target.value)}
+        placeholder="Type the corrected sentence…"
+        disabled={locked}
+        autoComplete="off"
+        spellCheck
+      />
+    </div>
+  )
+}

frontend/src/components/questions/NumericRange.tsx

@@ -0,0 +1,51 @@
+import type { Question } from '../../types'
+
+interface Props {
+  q: Question
+  value: number | string | null | undefined
+  onChange: (val: number) => void
+  locked?: boolean
+  graded?: boolean
+}
+
+export default function NumericRange({ q, value, onChange, locked, graded }: Props) {
+  const cfg = q.numericConfig
+  if (!cfg) {
+    return <div className="muted">Numeric config missing</div>
+  }
+
+  const min = cfg.min
+  const max = cfg.max
+  const numValue = value === '' || value == null ? '' : Number(value)
+
+  let cls = 'input numeric-input'
+  if (graded) {
+    const ok = typeof numValue === 'number' && !Number.isNaN(numValue) && Math.abs(numValue - cfg.answer) <= cfg.tolerance
+    cls += ok ? ' correct' : ' wrong'
+  }
+
+  return (
+    <div className="answer-input-wrap">
+      <input
+        className={cls}
+        type="number"
+        value={numValue}
+        onChange={(e) => {
+          const v = e.target.value
+          if (v === '') return
+          const n = Number(v)
+          if (!Number.isNaN(n)) onChange(n)
+        }}
+        placeholder="Enter number…"
+        disabled={locked}
+        min={min}
+        max={max}
+        step="any"
+      />
+      <div className="mono faint" style={{ fontSize: 11, marginTop: 4 }}>
+        Tolerance: ±{cfg.tolerance}
+        {min != null && max != null ? ` · Range: ${min} – ${max}` : ''}
+      </div>
+    </div>
+  )
+}

frontend/src/components/questions/QuestionRenderer.tsx

@@ -6,6 +6,14 @@ import MathInput from './MathInput'
 import Essay from './Essay'
 import Match from './Match'
 import OrderQuestion from './OrderQuestion'
+import FillInTheBlanks from './FillInTheBlanks'
+import TrueFalse from './TrueFalse'
+import CodeSubmission from './CodeSubmission'
+import DropdownCompletion from './DropdownCompletion'
+import NumericRange from './NumericRange'
+import Dictation from './Dictation'
+import GrammarCorrection from './GrammarCorrection'
+import Flashcard from './Flashcard'
 
 interface Props {
   q: Question
@@ -32,6 +40,22 @@ export default function QuestionRenderer({ q, value, onChange, locked, graded }:
       return <Match q={q} value={value as Record<string, string>} onChange={onChange as (v: Record<string, string>) => void} locked={locked} graded={graded} />
     case 'order':
       return <OrderQuestion q={q} value={value as string[]} onChange={onChange as (v: string[]) => void} locked={locked} graded={graded} />
+    case 'fill-in-the-blanks':
+      return <FillInTheBlanks q={q} value={value as Record<string, string>} onChange={onChange as (v: Record<string, string>) => void} locked={locked} graded={graded} />
+    case 'true-false':
+      return <TrueFalse q={q} value={value as boolean} onChange={onChange as (v: boolean) => void} locked={locked} graded={graded} />
+    case 'code-submission':
+      return <CodeSubmission q={q} value={value as Record<string, unknown>} onChange={onChange as (v: Record<string, unknown>) => void} locked={locked} />
+    case 'dropdown-completion':
+      return <DropdownCompletion q={q} value={value as Record<string, string>} onChange={onChange as (v: Record<string, string>) => void} locked={locked} graded={graded} />
+    case 'numeric-range':
+      return <NumericRange q={q} value={value as number} onChange={onChange as (v: number) => void} locked={locked} graded={graded} />
+    case 'dictation':
+      return <Dictation q={q} value={value as string} onChange={onChange as (v: string) => void} locked={locked} />
+    case 'grammar-correction':
+      return <GrammarCorrection q={q} value={value as string} onChange={onChange as (v: string) => void} locked={locked} graded={graded} />
+    case 'flashcard':
+      return <Flashcard q={q} value={value as { revealed?: boolean; selfGrade?: number }} onChange={onChange as (v: { revealed?: boolean; selfGrade?: number }) => void} locked={locked} />
     default:
       return <div className="muted">Unsupported question type: <code>{q.type}</code></div>
   }

frontend/src/components/questions/TrueFalse.tsx

@@ -0,0 +1,39 @@
+import type { Question } from '../../types'
+
+interface Props {
+  q: Question
+  value: boolean | null | undefined
+  onChange: (val: boolean) => void
+  locked?: boolean
+  graded?: boolean
+}
+
+export default function TrueFalse({ q, value, onChange, locked, graded }: Props) {
+  const correctAnswer = q.answer as boolean
+
+  return (
+    <div className="tf-group" role="radiogroup">
+      {[true, false].map((val) => {
+        const isSelected = value === val
+        let cls = 'tf-btn'
+        if (isSelected) cls += ' selected'
+        if (graded) {
+          if (val === correctAnswer) cls += ' correct'
+          else if (isSelected) cls += ' wrong'
+        }
+        return (
+          <button
+            key={val ? 't' : 'f'}
+            className={cls}
+            onClick={() => !locked && onChange(val)}
+            disabled={locked}
+            role="radio"
+            aria-checked={isSelected}
+          >
+            <span className="tf-label">{val ? 'True' : 'False'}</span>
+          </button>
+        )
+      })}
+    </div>
+  )
+}

frontend/src/contexts/AuthContext.tsx

@@ -9,6 +9,10 @@ export interface User {
   email: string
   displayName: string
   role: 'user' | 'admin'
+  storageQuotaBytes?: number
+  usedBytes?: number
+  usedPercent?: number
+  plan?: string
 }
 
 interface AuthContextValue {
@@ -18,7 +22,7 @@ interface AuthContextValue {
   setUser: (user: User | null) => void
   login: (email: string, password: string) => Promise<void>
   register: (email: string, password: string, displayName: string) => Promise<string>
-  logout: () => void
+  logout: () => Promise<void>
   refreshUser: () => Promise<void>
 }
 
@@ -47,7 +51,16 @@ export function AuthProvider({ children }: { children: ReactNode }) {
         return
       }
       const data = await authApi.getMe()
-      setUser({ id: data.id, email: data.email, displayName: data.displayName, role: (data.role as 'user' | 'admin') ?? 'user' })
+      setUser({
+        id: data.id,
+        email: data.email,
+        displayName: data.displayName,
+        role: (data.role as 'user' | 'admin') ?? 'user',
+        storageQuotaBytes: data.storageQuotaBytes,
+        usedBytes: data.usedBytes,
+        usedPercent: data.usedPercent,
+        plan: data.plan,
+      })
     } catch {
       clearToken()
       setUser(null)
@@ -63,7 +76,10 @@ export function AuthProvider({ children }: { children: ReactNode }) {
   const login = useCallback(async (email: string, password: string) => {
     const data = await authApi.login({ email, password })
     setToken(data.token)
-    setUser({ ...data.user, role: (data.user.role as 'user' | 'admin') ?? 'user' })
+    setUser({
+      ...data.user,
+      role: (data.user.role as 'user' | 'admin') ?? 'user',
+    })
   }, [])
 
   const register = useCallback(async (email: string, password: string, displayName: string): Promise<string> => {
@@ -71,7 +87,12 @@ export function AuthProvider({ children }: { children: ReactNode }) {
     return 'Registration successful! Please check your email to verify your account.'
   }, [])
 
-  const logout = useCallback(() => {
+  const logout = useCallback(async () => {
+    try {
+      await authApi.logout()
+    } catch {
+      // ignore errors — we still want to clear local state
+    }
     clearToken()
     setUser(null)
   }, [])