feat(cli): watch files with event streams

- Add a private SSE endpoint that emits file change events for authenticated clients.
- Replace the watch sleep loop with watchdog local file events and remote SSE triggers.
- Debounce local event bursts and keep watch running after transient sync failures.
- Add watchdog as a standalone CLI dependency and cover watch behavior in tests.
- Bump NanoShare to 1.25.0 and the standalone CLI to 0.4.0.

routes/__init__.py

@@ -21,6 +21,7 @@ from .side.upload import upload_bp
 
 from .api.cli_auth import cli_auth_bp
 from .api.download import api_download_bp
+from .api.events import api_events_bp
 
 # Health
 from .api.health import health_bp