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/main.py

@@ -1,4 +1,5 @@
 """Main FastAPI application entry point."""
+import logging
 from contextlib import asynccontextmanager
 from pathlib import Path
 from typing import AsyncGenerator
@@ -7,9 +8,13 @@ from fastapi import FastAPI, Request
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse, HTMLResponse
 from fastapi.staticfiles import StaticFiles
+from slowapi.errors import RateLimitExceeded
 
 from app.core.config import settings
 from app.core.database import close_db, init_db
+from app.core.rate_limiter import limiter
+
+logger = logging.getLogger(__name__)
 
 
 # Get the base directory
@@ -24,22 +29,22 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
     Handles startup and shutdown events.
     """
     # Startup
-    print("Starting up...")
+    logger.info("Starting up...")
     if settings.DEBUG:
-        print("Debug mode is ON")
-        print(f"Database URL: {settings.DATABASE_URL}")
-        print(f"Redis URL: {settings.FULL_REDIS_URL}")
+        logger.debug("Debug mode is ON")
+        logger.debug(f"Database URL: {settings.DATABASE_URL}")
+        logger.debug(f"Redis URL: {settings.FULL_REDIS_URL}")
 
     # Initialize database
     await init_db()
-    print("Database initialized")
+    logger.info("Database initialized")
 
     yield
 
     # Shutdown
-    print("Shutting down...")
+    logger.info("Shutting down...")
     await close_db()
-    print("Database connections closed")
+    logger.info("Database connections closed")
 
 
 # Create FastAPI application
@@ -53,6 +58,9 @@ app = FastAPI(
     lifespan=lifespan,
 )
 
+# Set up rate limiting
+app.state.limiter = limiter
+
 
 # Configure CORS
 app.add_middleware(
@@ -109,11 +117,12 @@ async def global_exception_handler(request, exc) -> JSONResponse:
 
 
 # API routes
-from app.api.v1 import auth, music, playlists
+from app.api.v1 import auth, music, playlists, library
 
 app.include_router(auth.router, prefix=settings.API_V1_PREFIX, tags=["authentication"])
 app.include_router(music.router, prefix=settings.API_V1_PREFIX, tags=["music"])
 app.include_router(playlists.router, prefix=settings.API_V1_PREFIX, tags=["playlists"])
+app.include_router(library.router, prefix=settings.API_V1_PREFIX, tags=["library"])
 
 # Mount static files
 static_dir = BASE_DIR / "app" / "static"