Phase 2: Tags UI, Custom Fields UI, Notifications Bell

- Tags UI: TagsPage (CRUD, color picker), TagBadge, TagSelector (multi-select, inline creation)
- Custom Fields Backend: model, schema, service, routes, migration 0041
- Custom Fields Frontend: CustomFieldsPage (definitions CRUD), CustomFieldRenderer (dynamic field rendering)
- Custom Fields: _collect_custom_field_definitions() extended to merge DB definitions with plugin definitions
- Notifications Bell: NotificationBell (30s polling, unread badge), NotificationDropdown, NotificationItem
- NotificationBell integrated into TopBar
- Routes: /tags, /settings/custom-fields registered
- Settings nav: Custom Fields entry added
- Menu items: Tags added to automation plugin manifest

app/main.py

@@ -49,6 +49,7 @@ from app.routes import (
     sequences,
     system_settings,
     attachments,
+    custom_field_definitions,
     custom_fields,
     saved_filters,
 )
@@ -330,6 +331,7 @@ def create_app() -> FastAPI:
     app.include_router(addresses.router)
     app.include_router(bank_accounts.router)
     app.include_router(audit.router)
+    app.include_router(custom_field_definitions.router)
     app.include_router(custom_fields.router)
     app.include_router(saved_filters.router)