FIX: Đã fix (v202608060430) — tab deactive → stop âm tab đó

app/static/js/app.precompiled.js

@@ -631,7 +631,11 @@ useEffect(()=>{const all=[...(tracks||[]),...(sessionTabs||[]).reduce((acc,s)=>a
 const audioSig=list.map(t=>(t.muted?'1':'0')+(t.solo?'1':'0')+':'+(t.volumeDb??0)+':'+(t.audioBypass?'1':'0')+(t.midiBypass?'1':'0')+':'+(t.midiItems||[]).length+':'+(t.clips||[]).length+':'+(t.sections||[]).length).join('|');if(trackAudioSyncSigRef.current===audioSig)return;trackAudioSyncSigRef.current=audioSig;list.forEach(t=>{// ♪ state → SF mastering route (sfRouteGain/sfDryGain), live on existing nodes
 const sn=activeTrackNodesRef.current[t.id];if(sn&&sn.sfRouteGain&&sn.sfDryGain&&sn.sfRouteGain.gain.value>0!==!effMidiBypass(t)){const _b=effMidiBypass(t);sn.sfRouteGain.gain.value=_b?0:1;sn.sfDryGain.gain.value=_b?1:0;}const sig=(t.muted?'1':'0')+(t.solo?'1':'0')+':'+(t.volumeDb??0);if(trackMuteSoloSigRef.current[t.id]===sig)return;trackMuteSoloSigRef.current[t.id]=sig;const audible=computeTrackAudibleGain(list,t)>0;const node=activeTrackNodesRef.current[t.id];const audibleGain=computeTrackAudibleGain(list,t);if(node)setTrackNodeGain(node,audibleGain);if(node&&node.sfEntry){try{const g=typeof audibleGain==='number'&&isFinite(audibleGain)&&!isNaN(audibleGain)?audibleGain:1.0;node.sfEntry.gain.setTargetAtTime(g,getAudioContext().currentTime,0.02);}catch(e){}}// MIDI tracks: mirror the gain decision onto the channel CC7 volume so
 // FluidSynth-rendered notes respect mute/solo too.
-if(t.midiItems&&t.midiItems.length>0||t.type==='MIDI'){try{if(window.SonicSF&&typeof window.SonicSF.controllerChange==='function'){const ch=ensureTrackMidiChannel(t,list);window.SonicSF.controllerChange(ch,7,audible?100:0);}}catch(e){}}trackAudibleRef.current[t.id]=audible;});updateSfRouting();},[tracks,sessionTabs]);useEffect(()=>{updateSfRouting();},[activeTab]);const[selectionCleared,setSelectionCleared]=useState(false);// LOOP_EDITOR_2.md §4.2
+if(t.midiItems&&t.midiItems.length>0||t.type==='MIDI'){try{if(window.SonicSF&&typeof window.SonicSF.controllerChange==='function'){const ch=ensureTrackMidiChannel(t,list);window.SonicSF.controllerChange(ch,7,audible?100:0);}}catch(e){}}trackAudibleRef.current[t.id]=audible;});updateSfRouting();},[tracks,sessionTabs]);const prevActiveTabRef=useRef(activeTab);useEffect(()=>{const prevTab=prevActiveTabRef.current;prevActiveTabRef.current=activeTab;updateSfRouting();// Tab DEACTIVE → stop âm của tab đó (user requirement): rời khỏi sub-tab
+// (PIANO_ROLL/section/audio tab) đang play → stop playback của tab đó.
+// Tab mới hoạt động bình thường; MAIN giữ hành vi cũ (mở piano-roll lúc
+// main play → main tiếp tục — handleEditMidiInTab đã xử lý).
+if(prevTab!==activeTab){const prevSub=subTabsRef.current.find(s=>s.id===prevTab);if(prevSub&&prevSub.isPlaying){try{stopAllPlayback();}catch(e){}setSubTabs(prev=>prev.map(s=>s.id===prevTab?{...s,isPlaying:false}:s));}}},[activeTab]);const[selectionCleared,setSelectionCleared]=useState(false);// LOOP_EDITOR_2.md §4.2
 const midiVuActivityRef=useRef({});const triggerMidiVuActivity=(trackId,velocity)=>{if(!trackId)return;const velFactor=typeof velocity==='number'?velocity>1?velocity/127:velocity:0.8;const peak=Math.min(1.0,Math.max(0.15,velFactor));midiVuActivityRef.current[trackId]=peak;};window.triggerMidiVuActivity=triggerMidiVuActivity;// ── Temp Edit Tab (LOOP_EDITOR_2.md §1.2 Sub Tab) ──
 const[tempTabActive,setTempTabActive]=useState(false);const[tempTabBuffer,setTempTabBuffer]=useState(null);const[tempTabTrackId,setTempTabTrackId]=useState(null);const[tempTabOrigStart,setTempTabOrigStart]=useState(0);const[tempTabOrigEnd,setTempTabOrigEnd]=useState(0);const tempTabCanvasRef=useRef(null);// Effect parameters for temp tab
 const[tempTabEffects,setTempTabEffects]=useState({reverse:false,gainDb:0,fadeInMs:0,fadeOutMs:0});// ── Auth / User State ──