chore: migrate all FA icons to Lucide (@lucide/svelte)

- Replaced all active FontAwesome <span class="fas fa-*"> icons with
  Lucide components across 145 files (excluding /idaa/ which is intentional)
- Fixed merge script bug: consolidated lucide-svelte imports into @lucide/svelte
- Replaced dynamic toggle patterns (fa-toggle-on/off) with ToggleRight/ToggleLeft
- Replaced fa-eye/fa-eye-slash with Eye/EyeOff
- Replaced fa-bug/fa-bug-slash with Bug/BugOff
- Replaced fa-sync fa-spin with RefreshCw + animate-spin
- Replaced fa-microchip with Cpu
- Fixed {@const} placement in element_manage_event_file_li.svelte
- Removed obsolete CSS hover rules for .unlock_icon/.lock_icon
- svelte-check: 0 errors, 0 warnings

src/routes/+layout.svelte

@@ -38,12 +38,13 @@
     // *** Import Aether specific variables and functions
     // import Analytics from '$lib/app_components/analytics.svelte';
     import { ae_loc, ae_sess, ae_api, slct, slct_trigger, ae_auth_error } from '$lib/stores/ae_stores';
-    import { LoaderCircle } from 'lucide-svelte';
+    import { LoaderCircle } from '@lucide/svelte';
     // import { events_loc, events_slct } from '$lib/stores/ae_events_stores';
 
     // import MyClipboard from '$lib/app_components/e_app_clipboard.svelte';
     import E_app_debug_menu from '$lib/app_components/e_app_debug_menu.svelte';
     import E_app_sys_bar from '$lib/app_components/e_app_sys_bar.svelte';
+    import { pwa_install } from '$lib/pwa/pwa_install.svelte';
     // import E_app_sys_menu from '$lib/app_components/e_app_sys_menu.svelte'; // replaced by E_app_sys_bar
 
     interface Props {
@@ -227,6 +228,9 @@
     $effect(() => {
         if (!browser) return;
 
+        // Initialise PWA install prompt listener (captures beforeinstallprompt early).
+        pwa_install.init();
+
         // Save DS to local
         let ae_ds = ae_acct?.ds;
         if (ae_ds) {