prod: UI Optimisée mise en production

- Documentation archivée et réorganisée
- Backend: Ajout tests, migrations, library service, rate limiting
- Frontend: Suppression Flutter, focus sur interface web HTML/JS
- Tailwind CSS ajouté pour le style
- Améliorations UX et corrections bugs

Generated with [Claude Code](https://claude.com/claude-code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

backend/app/schemas/auth.py

@@ -76,3 +76,10 @@ class RefreshTokenRequest(BaseModel):
     """Schema for token refresh request."""
 
     refresh_token: str
+
+
+class ChangePasswordRequest(BaseModel):
+    """Schema for password change request."""
+
+    old_password: str = Field(..., min_length=8, max_length=100)
+    new_password: str = Field(..., min_length=8, max_length=100)