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/core/rate_limiter.py

@@ -0,0 +1,24 @@
+"""Rate limiter configuration."""
+from slowapi import Limiter, _rate_limit_exceeded_handler
+from slowapi.util import get_remote_address
+from fastapi import Request
+from fastapi.responses import JSONResponse
+
+# Create limiter instance
+limiter = Limiter(key_func=get_remote_address)
+
+# Custom rate limit exceeded handler
+def rate_limit_exceeded_handler(request: Request, exception):
+    """Custom handler for rate limit exceeded."""
+    return JSONResponse(
+        status_code=429,
+        content={"detail": "Too many requests. Please try again later."},
+    )
+
+# Replace the default handler
+limiter._rate_limit_exceeded_handler = rate_limit_exceeded_handler
+
+# Rate limit rules
+# Example: 100 requests per minute for general endpoints
+# 10 requests per minute for authentication endpoints
+# 5 requests per second for expensive operations