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.

documentation/SVELTE_DEXIE_GUIDE.md

@@ -92,6 +92,35 @@ export function createLiveQueryStore<T>(query: () => T | Promise<T>) {
 
 The `createLiveQueryStore` function creates a readable store that automatically updates whenever the data in the `friends` table changes. The `$friends` variable in the component will always contain the latest data from the database.
 
+## Svelte 5 Binding Pitfalls
+
+### 1. `props_invalid_value` (The "Expression Binding" Error)
+Svelte 5's `bind:` directive is more restrictive than previous versions. You can only bind to a simple **Identifier** or **MemberExpression**.
+
+**❌ Invalid Pattern (Causes Compile Error):**
+Attempting to normalize a value *inside* the binding will fail.
+```svelte
+<!-- Error: Can only bind to an Identifier or MemberExpression -->
+<Launcher_menu bind:slct__event_session_id={$events_slct.event_session_id || null} />
+```
+
+**✅ Correct Pattern:**
+Ensure the source value is already normalized before binding, or use a reactive effect to handle the fallback.
+```typescript
+// Normalize in an effect or derivation
+$effect(() => {
+    if ($events_slct.event_session_id === undefined) {
+        $events_slct.event_session_id = null;
+    }
+});
+```
+```svelte
+<!-- Bind directly to the normalized property -->
+<Launcher_menu bind:slct__event_session_id={$events_slct.event_session_id} />
+```
+
+---
+
 ## Safe Data Processing for IndexedDB Sorting
 
 When preparing data for IndexedDB, especially when creating composite sort keys, it is critical to handle `null` or `undefined` values safely to prevent runtime crashes that can interrupt the data synchronization process.

src/lib/ae_events/ae_events__event_session.ts

@@ -196,7 +196,12 @@ export async function load_ae_obj_li__event_session({
                 if (log_lvl) console.log(`✅ [Trace] load_ae_obj_li: CACHE HIT at ${elapsed}ms (${cached_li.length} items).`);
                 
                 // Background refresh (non-blocking)
-                _refresh_session_li_background({ api_cfg, for_obj_type, for_obj_id, inc_file_li, inc_all_file_li, inc_presentation_li, inc_presenter_li, enabled, hidden, limit, offset, order_by_li, try_cache, log_lvl: log_lvl > 1 ? log_lvl : 0 });
+                _refresh_session_li_background({ 
+                    api_cfg, for_obj_type, for_obj_id, view, 
+                    inc_file_li, inc_all_file_li, inc_presentation_li, inc_presenter_li, 
+                    enabled, hidden, limit, offset, order_by_li, try_cache, 
+                    log_lvl: log_lvl > 1 ? log_lvl : 0 
+                });
                 
                 return cached_li;
             } else if (log_lvl) {
@@ -207,15 +212,15 @@ export async function load_ae_obj_li__event_session({
         }
     }
 
-    return await _refresh_session_li_background({ api_cfg, for_obj_type, for_obj_id, inc_file_li, inc_all_file_li, inc_presentation_li, inc_presenter_li, enabled, hidden, limit, offset, order_by_li, try_cache, log_lvl });
+    return await _refresh_session_li_background({ api_cfg, for_obj_type, for_obj_id, view, inc_file_li, inc_all_file_li, inc_presentation_li, inc_presenter_li, enabled, hidden, limit, offset, order_by_li, try_cache, log_lvl });
 }
 
-async function _refresh_session_li_background({ api_cfg, for_obj_type, for_obj_id, inc_file_li, inc_all_file_li, inc_presentation_li, inc_presenter_li, enabled, hidden, limit, offset, order_by_li, try_cache, log_lvl }: any) {
+async function _refresh_session_li_background({ api_cfg, for_obj_type, for_obj_id, view, inc_file_li, inc_all_file_li, inc_presentation_li, inc_presenter_li, enabled, hidden, limit, offset, order_by_li, try_cache, log_lvl }: any) {
     const start_time = performance.now();
     if (typeof navigator !== 'undefined' && !navigator.onLine) return [];
     try {
-        if (log_lvl) console.log(`📡 [Trace] _refresh_session_li: API Fetching for=${for_obj_type}:${for_obj_id}`);
-        const result_li = await api.get_ae_obj_li_v3({ api_cfg, obj_type: 'event_session', for_obj_type, for_obj_id, enabled, hidden, limit, offset, order_by_li, log_lvl });
+        if (log_lvl) console.log(`📡 [Trace] _refresh_session_li: API Fetching for=${for_obj_type}:${for_obj_id} (view=${view})`);
+        const result_li = await api.get_ae_obj_li_v3({ api_cfg, obj_type: 'event_session', for_obj_type, for_obj_id, view, enabled, hidden, limit, offset, order_by_li, log_lvl });
         
         if (result_li) {
             const processed = await process_ae_obj__event_session_props({ obj_li: result_li, log_lvl });

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: {},

src/routes/events/[event_id]/(launcher)/launcher/[event_location_id]/+page.ts

@@ -59,6 +59,7 @@ export async function load({ params, parent, url }) {
             inc_presenter_li: true,
             enabled: 'enabled',
             hidden: 'all',
+            view: 'alt', // Standardized View for file counts and extended metadata
             limit: 150,
             log_lvl: 0
         });

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

@@ -92,6 +92,7 @@
 
     async function handle_open_file() {
         if (log_lvl) console.log('*** handle_open_file() ***');
+        if (open_file_clicked) return; // Hard Guard: Already processing
 
         $events_slct.event_file_id = event_file_id;
         $events_slct.event_file_obj = event_file_obj;
@@ -107,7 +108,8 @@
 
             const exists = await native.check_hash_file_cache({
                 cache_root,
-                hash: event_file_obj.hash_sha256
+                hash: event_file_obj.hash_sha256,
+                verify_hash: true // Hardened: Trust No One!
             });
 
             if (!exists) {

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

@@ -1,13 +1,13 @@
 <script lang="ts">
     interface Props {
-        slct__event_session_id?: string;
+        slct__event_session_id?: string | null;
         lq__event_session_obj: any;
         type_code?: string;
         log_lvl?: number;
     }
 
     let {
-        slct__event_session_id = $bindable(''),
+        slct__event_session_id = $bindable(null),
         lq__event_session_obj,
         type_code = $bindable(''),
         log_lvl = $bindable(1)