fix(launcher): resolve hydration errors and missing file counts

- Initialized event_session_id to null in store template to prevent Svelte 5 binding errors.\n- Fixed invalid bind expressions in Launcher layout.\n- Corrected view: alt propagation in session list background refresh to ensure file counts are retrieved.\n- Hardened duplicate launch protection with verify_hash enabled by default.\n- Updated SVELTE_DEXIE_GUIDE.md with binding pitfall documentation.

src/lib/stores/ae_events_stores.ts

@@ -667,6 +667,7 @@ const events_slct_obj_template: key_val = {
     event_presenter_obj: {},
 
     session_id: null,
+    event_session_id: null,
     session_obj: {},
     session_obj_li: [],
     event_session_obj: {},