refactor(sessions): standardize reactive search and fix list layout

- Migrated Session search to the debounced  pattern with Search Guards and shared observables.
- Implemented 'Remote First' toggle support (Edit Mode only) for background-only revalidation.
- Resolved 'each_key_duplicate' crash and fixed icon scaling issues in the session list.
- Restored missing session alert visibility for managers.
- Standardized store initialization to prevent reactivity loops.

src/lib/stores/ae_events_stores.ts

@@ -247,6 +247,10 @@ const events_local_data_struct: key_val = {
         qry__files_offset_seconds: null,
         qry__files_sort: 'created_on',
 
+        // New additions for search stabilization (Standardized Pattern 2026-01-27)
+        search_version: 0,
+        qry__remote_first: false,
+
         qry_and__file_count: true, // Essentially it should be greater than 0
 
         save_search_text: true,