FIX: Piano roll tab không xuất âm thanh qua mastering chain được recovery

app/static/js/app.jsx

@@ -17825,7 +17825,10 @@ const App = () => {
           if ((isPianoRoll ? nanOut : (pk < 0.001 || nanOut))) {
             masterSilenceFramesRef.current++;
             const sinceRebuild = performance.now() - (lastMasterRebuildTimeRef.current || 0);
-            if (masterSilenceFramesRef.current > 45 && sinceRebuild > 3000) {
+            // NaN = chain CHẾT chắc chắn → rebuild NGAY (3 frame ≈ 50ms).
+            // pk<0.001 (im lặng nghi ngờ — main) giữ 45 frame (750ms) để loại
+            // transient gap false-positive. Cooldown 3000 chống rebuild-loop.
+            if (masterSilenceFramesRef.current > (nanOut ? 3 : 45) && sinceRebuild > 3000) {
               masterSilenceFramesRef.current = 0;
               lastMasterRebuildTimeRef.current = performance.now();
               console.warn('[Recovery] Master silent while sources active — rebuilding audio graph');

app/templates/index.html

@@ -24,7 +24,7 @@
     <script src="/static/js/services/midiExtractor.js?v=202607281052"></script>
     <script src="/static/js/services/promptTemplateManager.js?v=202607281039"></script>
     <script src="/static/js/services/undoRedoEngine.js?v=202607290941"></script>
-    <script src="/static/js/app.precompiled.js?v=202608060000" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608060030" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {