feat: integrate AI grading functionality

- Added OpenAI package to backend dependencies for AI grading.
- Implemented new grading routes and services to handle AI grading requests.
- Updated admin settings to include AI provider configuration options.
- Enhanced frontend components to support AI grading, including UI for testing AI connection and displaying AI feedback.
- Updated results component to allow for AI-assisted grading and display of suggested grades.
- Added internationalization support for new AI grading features in both English and Dutch.

.claude/settings.local.json

@@ -33,7 +33,10 @@
       "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)"
     ]
   }
 }