feat(launcher): implement device heartbeat and background sync engine

- Hardened 'find_object_id' in Dexie to support 'event_' prefixed IDs.
- Implemented singleton 'LauncherBackgroundSync' in root launcher layout.
- Added V3-compliant heartbeat and room refresh cycles.
- Fixed redundant component imports and Skeleton UI prop errors.
- Added 'inc_file_li' support to event API loader.

src/lib/ae_events/ae_events__event_location.ts

@@ -5,6 +5,7 @@ import { db_save_ae_obj_li__ae_obj } from '$lib/ae_core/core__idb_dexie';
 import { db_events } from '$lib/ae_events/db_events';
 import type { ae_EventLocation } from '$lib/types/ae_types';
 import { load_ae_obj_li__event_file } from '$lib/ae_events/ae_events__event_file';
+import { load_ae_obj_li__event_session } from '$lib/ae_events/ae_events__event_session';
 
 const ae_promises: key_val = {};