feat(backend): settings, upload media, seed données démo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/main.py

@@ -36,9 +36,13 @@ app.include_router(tasks.router, prefix="/api")
 app.include_router(settings.router, prefix="/api")
 app.include_router(media.router, prefix="/api")
 
-# Note: le mount StaticFiles sera ajouté ici dans Task 6
-
 
 @app.get("/api/health")
 def health():
     return {"status": "ok"}
+
+
+# Monter uploads seulement si le dossier existe
+from fastapi.staticfiles import StaticFiles
+if os.path.isdir(UPLOAD_DIR):
+    app.mount("/uploads", StaticFiles(directory=UPLOAD_DIR, html=False), name="uploads")