feat(fxrt): hien thi telemetry stats tren UI (vi WebView2 khong mo devtools)

app/static/js/app.jsx

@@ -13508,6 +13508,13 @@ const addMasterVst = (path) => { const fx = (masterFxList || []).find(f => f.pat
   const previewAudioRef = React.useRef(null);
   const [addMasterVstSel, setAddMasterVstSel] = React.useState('');
   const [masterVstPickerOpen, setMasterVstPickerOpen] = React.useState(false);
+  // FX RT telemetry (WebView2 không mở được devtools → hiển thị thẳng trên UI).
+  const [fxRtStats, setFxRtStats] = React.useState(null);
+  React.useEffect(() => {
+    if (!isOpen) return;
+    const iv = setInterval(() => { if (fxRt && fxRt.stats) setFxRtStats({ ...fxRt.stats }); }, 2000);
+    return () => clearInterval(iv);
+  }, [isOpen]);
 
   // Wave Observer Refs & States
   const woCanvasRef = React.useRef(null);
@@ -14223,6 +14230,17 @@ const addMasterVst = (path) => { const fx = (masterFxList || []).find(f => f.pat
           </button>
         </div>
 
+        {/* FX RT TELEMETRY — WebView2 không mở devtools, hiển thị thẳng trên UI */}
+        <div id="fxrt-stats-ui" className="h-6 bg-slate-950 border-b border-slate-800 px-4 flex items-center gap-3 text-[10px] oz-font-mono shrink-0">
+          <span className="text-slate-500 font-bold uppercase tracking-widest">FXRT</span>
+          {fxRtStats ? (
+            <span className={fxRtStats.underruns > 0 || fxRtStats.silences > 0 ? 'text-red-400' : 'text-emerald-400'}>
+              u={fxRtStats.underruns} h={fxRtStats.holds} f={fxRtStats.fades} s={fxRtStats.silences} q={fxRtStats.queueLen} cap={fxRtStats.capDrops} fadeIn={fxRtStats.fadeIns}
+            </span>
+          ) : <span className="text-slate-600">off</span>}
+          {fxRtStats && (fxRtStats.underruns > 0 || fxRtStats.silences > 0) && <span className="text-red-400">⚠ main-thread stall? Giảm tải UI / tăng FILL</span>}
+        </div>
+
         {/* MAIN WORKSPACE */}
         <main className="flex-1 flex overflow-hidden min-h-0">
 

app/templates/index.html

@@ -51,7 +51,7 @@
     <script src="/static/js/services/promptTemplateManager.js?v=202607281039"></script>
     <script src="/static/js/services/undoRedoEngine.js?v=202607290941"></script>
     <script src="/static/js/services/chordTheory.js?v=202608211300"></script>
-    <script src="/static/js/app.precompiled.js?v=202608242100" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608242200" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {