fix(pres_mgmt): sort presentations by priority > sort > start_datetime > code > name

Replaced single-field sortBy('name') with toArray() + JS comparator to
implement the full desired sort chain. Dexie's sortBy() only supports a
single indexed field, so multi-field ordering requires a JS sort pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/events/[event_id]/(pres_mgmt)/session/[session_id]/+page.svelte

@@ -67,16 +67,40 @@ let lq__event_session_obj = $derived(
 );
 
 // 2. Presentation List Observable
+// WHY: Dexie sortBy() is single-field only. Multi-field sort requires toArray() + JS comparator.
+// Desired order: priority DESC → sort ASC → start_datetime ASC → code ASC → name ASC
 let lq__event_presentation_obj_li = $derived(
     liveQuery(async () => {
         if (log_lvl)
             console.log(
                 `[LQ] Querying Presentations for Session: ${url_session_id}`
             );
-        return await db_events.presentation
+        const results = await db_events.presentation
             .where('event_session_id')
             .equals(url_session_id)
-            .sortBy('name');
+            .toArray();
+        return results.sort((a, b) => {
+            // priority DESC (true first)
+            const pa = a.priority ? 1 : 0;
+            const pb = b.priority ? 1 : 0;
+            if (pb !== pa) return pb - pa;
+            // sort ASC
+            const sa = a.sort ?? 0;
+            const sb = b.sort ?? 0;
+            if (sa !== sb) return sa - sb;
+            // start_datetime ASC
+            const da = a.start_datetime ?? '';
+            const db_val = b.start_datetime ?? '';
+            if (da !== db_val) return da < db_val ? -1 : 1;
+            // code ASC
+            const ca = a.code ?? '';
+            const cb = b.code ?? '';
+            if (ca !== cb) return ca < cb ? -1 : 1;
+            // name ASC
+            const na = a.name ?? '';
+            const nb = b.name ?? '';
+            return na < nb ? -1 : na > nb ? 1 : 0;
+        });
     })
 );