fix: use ref-wrapped handler for delete selected items

Move delete logic into handleDeleteSelectedItemsRef to ensure
setSelectedItemIds, updateActiveTracks, showToast are always
up-to-date despite empty useEffect deps in keyboard handler.

Keyboard handler reads selectedItemIdsRef.current (live ref),
calls handleDeleteSelectedItemsRef.current(idsToDelete).

app/static/js/app.jsx

@@ -7717,6 +7717,38 @@ const App = () => {
   const handleRedoRef = useRef(handleRedo);
   handleUndoRef.current = handleUndo;
   handleRedoRef.current = handleRedo;
+  const handleDeleteSelectedItemsRef = useRef(() => {});
+  handleDeleteSelectedItemsRef.current = (idsToDelete) => {
+    const count = idsToDelete.size;
+    setSelectedItemIds(new Set());
+    updateActiveTracks(prev => prev.map(t => {
+      let changed = false;
+      const sections = (t.sections || []).filter(s => {
+        if (idsToDelete.has(s.id)) { changed = true; return false; }
+        return true;
+      });
+      const midiItems = (t.midiItems || []).filter(m => {
+        if (idsToDelete.has(m.id)) { changed = true; return false; }
+        return true;
+      });
+      const clips = (t.clips || []).filter(c => {
+        const canonical = c.id === 'default' ? 'default_' + t.id : c.id;
+        if (idsToDelete.has(canonical)) { changed = true; return false; }
+        return true;
+      });
+      if (!changed) return t;
+      return {
+        ...t,
+        sections,
+        midiItems,
+        clips,
+        buffer: clips[0]?.buffer || null,
+        startTime: clips[0]?.startTime || 0,
+        name: clips[0]?.name || t.name
+      };
+    }));
+    showToast(count === 1 ? 'Đã xóa 1 item.' : `Đã xóa ${count} items.`, 'info');
+  };
   const selectedClipIdRef = useRef(null);
   selectedClipIdRef.current = selectedClipId;
   const activeTabRef = useRef(activeTab);
@@ -8164,35 +8196,7 @@ const App = () => {
          if (selItems.size > 0) {
            e.preventDefault();
            const idsToDelete = new Set(selItems);
-           setSelectedItemIds(new Set());
-           updateActiveTracks(prev => prev.map(t => {
-             let changed = false;
-             const sections = (t.sections || []).filter(s => {
-               if (idsToDelete.has(s.id)) { changed = true; return false; }
-               return true;
-             });
-             const midiItems = (t.midiItems || []).filter(m => {
-               if (idsToDelete.has(m.id)) { changed = true; return false; }
-               return true;
-             });
-             const clips = (t.clips || []).filter(c => {
-               const canonical = c.id === 'default' ? 'default_' + t.id : c.id;
-               if (idsToDelete.has(canonical)) { changed = true; return false; }
-               return true;
-             });
-             if (!changed) return t;
-             return {
-               ...t,
-               sections,
-               midiItems,
-               clips,
-               buffer: clips[0]?.buffer || null,
-               startTime: clips[0]?.startTime || 0,
-               name: clips[0]?.name || t.name
-             };
-           }));
-           const count = idsToDelete.size;
-           showToast(count === 1 ? 'Đã xóa 1 item.' : `Đã xóa ${count} items.`, 'info');
+           handleDeleteSelectedItemsRef.current(idsToDelete);
            return;
          }
          const selClip = selectedClipIdRef.current;