extract background tasks into worker binary

Move auto_scheduler, library_sync, broadcast_poller, webhook_consumer
from presentation/background/ into crates/worker/src/jobs/.
Presentation is now a pure HTTP server.

crates/presentation/src/main.rs

@@ -4,7 +4,6 @@ use tower_http::cors::{Any, CorsLayer};
 use tower_http::trace::TraceLayer;
 use tracing::info;
 
-mod background;
 mod errors;
 mod extractors;
 mod factory;