feat: VSTi live playback 100% client-side (không Carla) — autosample SF2 backend (pedalboard) → FluidSynth WASM qua masterBus → mastering → main out; SonicVstiAutosample ensure+dedup+cooldown; runtime gating __enableCarlaLivePlayback; âm bắt qua ensureMidiCapture → clientSideExport

app/static/js/app.jsx

@@ -198,7 +198,7 @@ const isSfTrackEngine = (se) => {
 };
 const isVstTrackEngine = (se) => !!se && String(se.type || '').indexOf('vst') !== -1;
 // Track dùng VSTi + Carla local → route Carla (native GUI, realtime).
-const shouldRouteCarla = (se) => !!(window.SonicCarlaMidi && window.SonicCarlaMidi.shouldRoutePlayback(se));
+const shouldRouteCarla = () => false; // live playback 100% client (SF2 autosampled WASM) — không route Carla
 
 // ── Native soundfont preview (standalone) ─────────────────────────────────
 // Render 1 note bằng backend native FluidSynth (pyfluidsynth) → play WAV.
@@ -15492,6 +15492,11 @@ const App = () => {
     setInstrumentDropdownTrackId(null);
     setInstrumentDropdownBtnRect(null);
     setSynthCategory(null);
+    // VSTi live playback: pre-warm autosample (SF2 backend) — note đầu không bị
+    // delay (SonicSF cũng ensure lazily trong _playNoteFluid nếu chưa có).
+    if (window.SonicVstiAutosample && instrumentId && !isSfInstrument) {
+      window.SonicVstiAutosample.ensure({ plugin_id: instrumentId, type: 'vst3' });
+    }
     // Trigger FluidSynth load + program change when soundfont instrument selected
     if (window.SonicSF && window.SonicSF.selectInstrument && instrumentId && isSfInstrument) {
       const sfId = instrumentId.replace('sf_', '');
@@ -16398,6 +16403,10 @@ const App = () => {
       return;
     }
     updateActiveTracks(prev => prev.map(t => t.id === trackId ? { ...t, synth_engine: { ...(t.synth_engine || {}), preset_id: presetId } } : t));
+    // Autosample lại theo preset mới (key khác) — live playback dùng âm preset
+    if (window.SonicVstiAutosample && se.plugin_id) {
+      window.SonicVstiAutosample.ensure({ plugin_id: se.plugin_id, preset_id: presetId, type: 'vst3' });
+    }
     setInstrumentDropdownTrackId(null);
     setInstrumentDropdownBtnRect(null);
     var p = ((window.SonicRuntime && window.SonicRuntime.presets) || []).find(function (x) { return x.id === presetId; });