Fix page reset on save: disable reload, handle orphaned timers

- Set reload=False to prevent watchfiles from triggering full page
  reloads when JSON/DB files are written during save
- Timeline graph poll timer (200ms) now deactivates itself when its
  parent slot is deleted during UI refresh
- Comfy monitor poll timer catches RuntimeError from deleted parent
  slots instead of crashing

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

main.py

@@ -522,4 +522,4 @@ def render_sidebar(state: AppState, dual_pane: dict):
 if _shared_db is not None:
     register_api_routes(_shared_db)
 
-ui.run(title='AI Settings Manager', port=8080, reload=True, reload_includes=['*.py'])
+ui.run(title='AI Settings Manager', port=8080, reload=False)