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

routes/api/events.py

@@ -0,0 +1,51 @@
+from __future__ import annotations
+
+import asyncio
+import json
+
+from my_modules.app.setup import LIMITER
+from my_modules.decoratory.header import token_required
+from quart import Blueprint, Response, current_app, stream_with_context
+
+api_events_bp = Blueprint('api_events', __name__)
+
+async def _snapshot(user_id: str) -> str:
+  files = await current_app.convex.get_files(user_id)
+  rows = []
+  for item in files or []:
+    if not isinstance(item, dict):
+      continue
+    rows.append({
+      'file_id': item.get('file_id'),
+      'file_name': item.get('file_name'),
+      'file_path': item.get('file_path') or '',
+      'file_size': item.get('file_size'),
+      'expires_at': item.get('expires_at'),
+      'updated_at': item.get('updated_at') or item.get('uploaded_at'),
+    })
+  rows.sort(key=lambda row: str(row.get('file_id') or ''))
+  return json.dumps(rows, sort_keys=True, separators=(',', ':'))
+
+@api_events_bp.get('/api/files/events')
+@LIMITER.limit('6 per minute;60 per hour;')
+@token_required(['files', 'mesh'])
+async def api_file_events(user: dict):
+  user_id = user['sub']
+
+  @stream_with_context
+  async def stream():
+    previous = await _snapshot(user_id)
+    yield 'event: ready\ndata: {}\n\n'
+    while True:
+      await asyncio.sleep(30)
+      current = await _snapshot(user_id)
+      if current != previous:
+        previous = current
+        yield f'event: files.changed\ndata: {current}\n\n'
+      else:
+        yield ': keepalive\n\n'
+
+  return Response(stream(), content_type='text/event-stream', headers={
+    'Cache-Control': 'no-cache',
+    'X-Accel-Buffering': 'no',
+  })