feat: strengthen backup and mobile workflows

backend/main.py

@@ -29,6 +29,7 @@ from .auth import (
     session_token,
     verify_password,
 )
+from .backup import router as backup_router
 from .db import create_schema, get_db
 from .models import (
     AppState,
@@ -118,6 +119,7 @@ async def openapi(_: User = Depends(current_user)):
 
 
 app.include_router(mvp_router)
+app.include_router(backup_router)
 logger = logging.getLogger(__name__)
 _login_attempts: dict[tuple[str, str], deque[float]] = defaultdict(deque)