fix(launcher): resolve metadata flickering and harden session reactivity

- Standardized default view to 'alt' for session loading to ensure persistent file counts.\n- Hardened 'No files' warning logic to prevent false positives during background refreshes.\n- Restored reactive session observable in layout for global header and idle logic.\n- Documented overwrite pitfalls in SVELTE_DEXIE_GUIDE.md.

src/lib/ae_events/ae_events__event_session.ts

@@ -147,7 +147,7 @@ export async function load_ae_obj_li__event_session({
     inc_presenter_li = false,
     enabled = 'enabled',
     hidden = 'not_hidden',
-    view = 'default',
+    view = 'alt',
     limit = 100,
     offset = 0,
     order_by_li = [

src/routes/events/[event_id]/(launcher)/launcher_session_view.svelte

@@ -346,7 +346,7 @@
         {@html $lq__event_session_obj.description}
     </section> -->
 
-        {#if !$lq__event_session_obj?.file_count_all}
+        {#if $lq__event_session_obj?.file_count_all === 0}
             <p class="text-2xl text-center text-red-500 font-bold">
                 <span class="fas fa-exclamation-triangle"></span>
                 Warning