- Introduced a dual-token system for user authentication: a short-lived access token and a long-lived rotating refresh token.
- Created a new RefreshToken model to manage refresh tokens securely.
- Updated auth_api.py to handle login, refresh, and logout processes with the new token system.
- Enhanced security measures including token rotation and theft detection.
- Updated frontend to handle token refresh on 401 errors and adjusted SSE authentication.
- Removed CORS middleware as it's unnecessary behind the nginx proxy.
- Added tests to ensure functionality and security of the new token system.
- Added `marked_for_deletion` and `marked_for_deletion_at` fields to User model (Python and TypeScript) with serialization updates
- Created POST /api/user/mark-for-deletion endpoint with JWT auth, error handling, and SSE event trigger
- Blocked login and password reset for marked users; added new error codes ACCOUNT_MARKED_FOR_DELETION and ALREADY_MARKED
- Updated UserProfile.vue with "Delete My Account" button, confirmation modal (email input), loading state, success/error modals, and sign-out/redirect logic
- Synced error codes and model fields between backend and frontend
- Added and updated backend and frontend tests to cover all flows and edge cases
- All Acceptance Criteria from the spec are complete and verified
