feat: add i18next and react-i18next for internationalization support

frontend/package-lock.json

@@ -9,9 +9,12 @@
       "version": "0.0.0",
       "dependencies": {
         "dompurify": "^3.4.1",
+        "i18next": "^23.16.8",
+        "i18next-browser-languagedetector": "^8.0.4",
         "katex": "^0.16.45",
         "react": "^19.2.5",
         "react-dom": "^19.2.5",
+        "react-i18next": "^15.4.1",
         "react-router-dom": "^7.14.2"
       },
       "devDependencies": {
@@ -228,6 +231,15 @@
         "node": ">=6.0.0"
       }
     },
+    "node_modules/@babel/runtime": {
+      "version": "7.29.2",
+      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.29.2.tgz",
+      "integrity": "sha512-JiDShH45zKHWyGe4ZNVRrCjBz8Nh9TMmZG1kh4QTK8hCBTWBi8Da+i7s1fJw7/lYpM4ccepSNfqzZ/QvABBi5g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=6.9.0"
+      }
+    },
     "node_modules/@babel/template": {
       "version": "7.28.6",
       "resolved": "https://registry.npmjs.org/@babel/template/-/template-7.28.6.tgz",
@@ -2287,6 +2299,47 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/html-parse-stringify": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/html-parse-stringify/-/html-parse-stringify-3.0.1.tgz",
+      "integrity": "sha512-KknJ50kTInJ7qIScF3jeaFRpMpE8/lfiTdzf/twXyPBLAGrLRTmkz3AdTnKeh40X8k9L2fdYwEp/42WGXIRGcg==",
+      "license": "MIT",
+      "dependencies": {
+        "void-elements": "3.1.0"
+      }
+    },
+    "node_modules/i18next": {
+      "version": "23.16.8",
+      "resolved": "https://registry.npmjs.org/i18next/-/i18next-23.16.8.tgz",
+      "integrity": "sha512-06r/TitrM88Mg5FdUXAKL96dJMzgqLE5dv3ryBAra4KCwD9mJ4ndOTS95ZuymIGoE+2hzfdaMak2X11/es7ZWg==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://locize.com"
+        },
+        {
+          "type": "individual",
+          "url": "https://locize.com/i18next.html"
+        },
+        {
+          "type": "individual",
+          "url": "https://www.i18next.com/how-to/faq#i18next-is-awesome.-how-can-i-support-the-project"
+        }
+      ],
+      "license": "MIT",
+      "dependencies": {
+        "@babel/runtime": "^7.23.2"
+      }
+    },
+    "node_modules/i18next-browser-languagedetector": {
+      "version": "8.2.1",
+      "resolved": "https://registry.npmjs.org/i18next-browser-languagedetector/-/i18next-browser-languagedetector-8.2.1.tgz",
+      "integrity": "sha512-bZg8+4bdmaOiApD7N7BPT9W8MLZG+nPTOFlLiJiT8uzKXFjhxw4v2ierCXOwB5sFDMtuA5G4kgYZ0AznZxQ/cw==",
+      "license": "MIT",
+      "dependencies": {
+        "@babel/runtime": "^7.23.2"
+      }
+    },
     "node_modules/ignore": {
       "version": "5.3.2",
       "resolved": "https://registry.npmjs.org/ignore/-/ignore-5.3.2.tgz",
@@ -3089,6 +3142,32 @@
         "react": "^19.2.5"
       }
     },
+    "node_modules/react-i18next": {
+      "version": "15.7.4",
+      "resolved": "https://registry.npmjs.org/react-i18next/-/react-i18next-15.7.4.tgz",
+      "integrity": "sha512-nyU8iKNrI5uDJch0z9+Y5XEr34b0wkyYj3Rp+tfbahxtlswxSCjcUL9H0nqXo9IR3/t5Y5PKIA3fx3MfUyR9Xw==",
+      "license": "MIT",
+      "dependencies": {
+        "@babel/runtime": "^7.27.6",
+        "html-parse-stringify": "^3.0.1"
+      },
+      "peerDependencies": {
+        "i18next": ">= 23.4.0",
+        "react": ">= 16.8.0",
+        "typescript": "^5"
+      },
+      "peerDependenciesMeta": {
+        "react-dom": {
+          "optional": true
+        },
+        "react-native": {
+          "optional": true
+        },
+        "typescript": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/react-router": {
       "version": "7.14.2",
       "resolved": "https://registry.npmjs.org/react-router/-/react-router-7.14.2.tgz",
@@ -3612,6 +3691,15 @@
         }
       }
     },
+    "node_modules/void-elements": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/void-elements/-/void-elements-3.1.0.tgz",
+      "integrity": "sha512-Dhxzh5HZuiHQhbvTW9AMetFfBHDMYpo23Uo9btPXgdYP+3T5S+p+jgNy7spra+veYhBP2dCSgxR/i2Y02h5/6w==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/which": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/which/-/which-2.0.2.tgz",