M26: fix pdc=wet-lag FILL (10240) + sync display/anchor - het upbeat khi PWR ON giua play

- FX_RT_ROUNDTRIP_SAMPLES (12032) -> FX_RT_WET_LAG_SAMPLES (10240 = FILL 40 block)
- fxRtApplyPdc + OFF-rebase + wake-rebase + bridge pos + playhead (main/sub/PR):
  tru latencyTotal (VST report 17536~365ms, content-latency that ~0) -> wet-lag
- xoa diag M26b wake + M26 OFF (ph_on_*/ph_echo), giu ph_* logs guarded

app/static/js/app.jsx

@@ -2149,29 +2149,6 @@ async function fxRtStart() {
       fxRt.inQueue = [];
       fxRt.outL = null;
       fxRt.outR = null;
-      // M26b diag: PWR ON wake — snap pdcDelay/gains + hoi worklet state luc
-      // wake, luc 'started' (wet bat dau) + 180/400/800ms sau: do wet-lag that,
-      // delay node co ve 0 truoc crossfade khong. Bo diag o build fix.
-      let _m26onWlArmed = false;
-      const _snapOn = (tag, _sched) => {
-        let _pd='na',_gd='na',_gw='na',_ps='na',_pa='na';
-        const _b=masterBus, _c=getAudioContext();
-        try { if(_b&&_b.pdcDelay) _pd=(_b.pdcDelay.delayTime.value*1000).toFixed(1); } catch(e){}
-        try { if(_b&&_b.masterFxDryGain) _gd=_b.masterFxDryGain.gain.value.toFixed(4); } catch(e){}
-        try { if(_b&&_b.masterFxGain) _gw=_b.masterFxGain.gain.value.toFixed(4); } catch(e){}
-        try { _ps=typeof fxRt.processedSamples==='number'?fxRt.processedSamples:'na'; } catch(e){}
-        try { _pa=typeof fxRt.processedAnchor==='number'?fxRt.processedAnchor:'na'; } catch(e){}
-        _dbgLog(tag,'pdcMs='+_pd+' gDry='+_gd+' gWet='+_gw+' lat='+(fxRt.latencyTotal||0)+' ps='+_ps+' pa='+_pa+' act='+(fxRt.active?1:0)+' warm='+(fxRt.warm?1:0)+' faded='+(fxRt.fadedIn?1:0)+' ctx='+(_c?_c.currentTime.toFixed(3):'na'));
-        try { if (fxRt.node && fxRt.node.port) fxRt.node.port.postMessage({ type: 'dbg_state', k: tag }); } catch(e){}
-        if (_sched && _sched.length) _sched.forEach((_ms,_ix)=>setTimeout(()=>_snapOn('ph_on'+( _ix+1)),_ms));
-      };
-      try { if (fxRt.node && fxRt.node.port && !_m26onWlArmed) {
-        _m26onWlArmed = true;
-        const _wl = (ev) => { try { const d = ev.data; if (d && d.type === 'dbg_state_r') _dbgLog('ph_on_wl','k='+d.k+' t='+d.t+' q='+d.q+' play='+d.playing+' hs='+d.hasStarted+' sil='+d.silenced+' fp='+d.flushPending+' stp='+d.stopped+' wm='+d.wrapMode+' wfb='+d.wrapFadeBlocks+' lat='+d.latencySamples+' rfill='+d.resumeFill+' inC='+d.inCount+' outPos='+d.outPos+' fadeL='+d.fadeLeft+' holdL='+d.holdFadeLeft); } catch(e){} };
-        fxRt.node.port.addEventListener('message', _wl);
-        setTimeout(()=>{ try { if (fxRt.node && fxRt.node.port) fxRt.node.port.removeEventListener('message', _wl); } catch(e){} }, 2600);
-      } } catch(e){}
-      _snapOn('ph_on_a', null);
       // M19 Bug A fix: wake PWR ON sau warm-bypass. Trước đây chỉ flush engine
       // ring + fadedIn=true NGAY — nhưng worklet lúc bypass rời graph không
       // process: outQueue còn ~FILL block audio CŨ + hasStarted=true (không gửi
@@ -2192,7 +2169,6 @@ async function fxRtStart() {
         try {
           if (ev.data && ev.data.type === 'started' && wToken === fxRt.startToken) {
             fxRt.fadedIn = true;
-            try { _snapOn('ph_on_s', [180, 400, 800]); } catch (e) {}
             fxRtCrossfade(true, wToken);
             setTimeout(() => { if (wToken === fxRt.startToken) fxRtApplyPdc(); }, 250);
           }
@@ -2658,13 +2634,15 @@ async function fxRtEnsureWarmForGui(path) {
 // Master chain (worklet → bridge VST3) trễ ~2 block round-trip + latency
 // plugin. Track bypass mastering đi dry path (dryInput→dryOutput→output) KHÔNG
 // qua worklet → lệch pha với mastered. fxRtApplyPdc trễ dry path đúng lượng
-// để align. FX_RT_ROUNDTRIP_SAMPLES là ước lượng — ponytail: đo RTT thật
-// (tag seq trên block) khi cần sample-accurate.
-// M18: FILL 40 (sf-fx-realtime.js V48) → RTT = batching 4 block (~7 block @48k
-// ≈ 1792) + FILL buffer 40 block (10240) = 47 block ≈ 12032 (~251ms @48k). Giữ
-// đồng bộ với sf-fx-realtime.js. FX_RT_START_EST_MS: ước lượng khởi đầu khi
-// chưa có phép đo (fx_play_first) — dùng cho freeze playhead thay V39 0.31s.
-const FX_RT_ROUNDTRIP_SAMPLES = 12032;
+// de align. M26: pdc = wet-lag FILL - content nghe = S(t-FILL); M26b do onset
+// +208-221ms = FILL 40 block (10240 @48k ~213ms) + RTT nho. KHONG tin VST
+// report (Ozone bao 17536 ~365ms nhung content-latency that ~0). ponytail:
+// neu plugin content-latency that L>0 -> pdc = FILL + L (display-lat giu FILL
+// vi processed da gom L).
+// Dong bo voi sf-fx-realtime.js: FILL 40 block (10240 @48k). FX_RT_START_EST_MS:
+// uoc luong khoi dau khi chua co phep do (fx_play_first) - dung cho freeze
+// playhead thay V39 0.31s.
+const FX_RT_WET_LAG_SAMPLES = 10240;
 const FX_RT_START_EST_MS = 450;
 // G3: anchor processed — playhead = startOffset + (processed - anchor - latency)/sr
 // (da tru latency -> bam vi tri mau NGHE DUOC; pre-roll tu giu tai startOffset —
@@ -2687,11 +2665,10 @@ function fxRtApplyPdc() {
   const ctx = getAudioContext();
   const bus = masterBus;
   if (!ctx || !bus || !bus.pdcDelay) return;
-  // M23 Bug C: bo +FX_RT_ROUNDTRIP_SAMPLES — latencyTotal (bridge 'latency'
-  // frame) DA gom round-trip that (log M21/M22: display active = wall - lat).
-  // +12032 double-count -> dry path delay > wet lag ~250ms -> crossfade lech pha
-  // (scratch). ponytail: neu engine pipeline doi RTT that -> do lai o day.
-  const l = (fxRt && fxRt.active) ? (fxRt.latencyTotal || 0) : 0;
+  // M26: pdc = wet-lag FILL 10240 (~213ms) - content nghe = S(t-FILL); VST
+  // report (17536) la plugin buffer, content-latency that ~0 (M26b do onset).
+  // ponytail: neu content-latency that L>0 -> FX_RT_WET_LAG_SAMPLES + L.
+  const l = (fxRt && fxRt.active) ? FX_RT_WET_LAG_SAMPLES : 0;
   try { bus.pdcDelay.delayTime.setTargetAtTime(l / (ctx.sampleRate || 44100), ctx.currentTime, 0.05); } catch (e) {}
 }
 
@@ -21022,10 +20999,10 @@ const App = () => {
                     const _off2 = startOffsetTimeRef.current || 0;
                     const _at2 = startAudioTimeRef.current || _c2.currentTime;
                     const _eng2 = (typeof fxRt.processedSamples === 'number' && fxRt.processedAnchor != null)
-                      ? Math.max(_off2, _off2 + (fxRt.processedSamples - fxRt.processedAnchor - (fxRt.latencyTotal || 0)) / _sr2)
+                      ? Math.max(_off2, _off2 + (fxRt.processedSamples - fxRt.processedAnchor - FX_RT_WET_LAG_SAMPLES) / _sr2)
                       : null;
                     const _wall2 = _off2 + (_c2.currentTime - _at2);
-                    const _content2 = (_eng2 !== null) ? _eng2 : (_wall2 - (fxRt.latencyTotal || 0) / _sr2);
+                    const _content2 = (_eng2 !== null) ? _eng2 : (_wall2 - FX_RT_WET_LAG_SAMPLES / _sr2);
                     startOffsetTimeRef.current = _content2;
                     startAudioTimeRef.current = _c2.currentTime;
                     _dbgLog('ph_offhold', 'cur=' + (currentTimeRef.current == null ? 'na' : currentTimeRef.current.toFixed(3)) + ' wall=' + _wall2.toFixed(3) + ' content=' + _content2.toFixed(3) + ' off=' + startOffsetTimeRef.current.toFixed(3) + ' at=' + startAudioTimeRef.current.toFixed(3) + ' ctx=' + _c2.currentTime.toFixed(3) + ' lat=' + (fxRt.latencyTotal || 0) + ' hold=1');
@@ -21034,38 +21011,6 @@ const App = () => {
                   }
                 } catch (e) { try { _dbgLog('ph_offhold', 'err ' + String(e)); } catch (e2) {} }
                 fxRtWarmBypass();
-                // M26 diag: PWR OFF mid-play — snap pdcDelay/gains + hoi worklet
-                // state tai t0/+180/+400/+800ms de do: pdc thuc te khi dry mo,
-                // wet tail song bao lau, gains ramp ra sao. Bo diag o build fix.
-                if (_plNow) {
-                  const _busB = masterBus;
-                  const _ctxB = getAudioContext();
-                  const _snapB = (k) => {
-                    let _pdB = 'na', _gdB = 'na', _gwB = 'na', _psB = 'na', _paB = 'na';
-                    try { if (_busB && _busB.pdcDelay) _pdB = (_busB.pdcDelay.delayTime.value * 1000).toFixed(1); } catch (e) {}
-                    try { if (_busB && _busB.masterFxDryGain) _gdB = _busB.masterFxDryGain.gain.value.toFixed(4); } catch (e) {}
-                    try { if (_busB && _busB.masterFxGain) _gwB = _busB.masterFxGain.gain.value.toFixed(4); } catch (e) {}
-                    try { _psB = typeof fxRt.processedSamples === 'number' ? fxRt.processedSamples : 'na'; } catch (e) {}
-                    try { _paB = typeof fxRt.processedAnchor === 'number' ? fxRt.processedAnchor : 'na'; } catch (e) {}
-                    const _oB = startOffsetTimeRef.current || 0;
-                    const _aB = startAudioTimeRef.current || 0;
-                    const _tB = _ctxB ? _ctxB.currentTime : 0;
-                    _dbgLog('ph_echo' + k, 'pdcMs=' + _pdB + ' gDry=' + _gdB + ' gWet=' + _gwB + ' lat=' + (fxRt.latencyTotal || 0) + ' ps=' + _psB + ' pa=' + _paB + ' cur=' + (currentTimeRef.current == null ? 'na' : currentTimeRef.current.toFixed(3)) + ' off=' + _oB.toFixed(3) + ' wall=' + (_oB + _tB - _aB).toFixed(3) + ' ctx=' + _tB.toFixed(3));
-                    try { if (fxRt.node && fxRt.node.port) fxRt.node.port.postMessage({ type: 'dbg_state', k: k }); } catch (e) {}
-                  };
-                  const _wlB = (ev) => {
-                    try {
-                      const d = ev.data;
-                      if (d && d.type === 'dbg_state_r') {
-                        _dbgLog('ph_echo_wl', 'k=' + d.k + ' t=' + d.t + ' q=' + d.q + ' play=' + d.playing + ' hs=' + d.hasStarted + ' sil=' + d.silenced + ' fp=' + d.flushPending + ' stp=' + d.stopped + ' wm=' + d.wrapMode + ' wfb=' + d.wrapFadeBlocks + ' lat=' + d.latencySamples + ' rfill=' + d.resumeFill + ' inC=' + d.inCount + ' outPos=' + d.outPos + ' fadeL=' + d.fadeLeft + ' holdL=' + d.holdFadeLeft);
-                      }
-                    } catch (e) {}
-                  };
-                  try { if (fxRt.node && fxRt.node.port) fxRt.node.port.addEventListener('message', _wlB); } catch (e) {}
-                  _snapB(0);
-                  [180, 400, 800].forEach((_msB, _iB) => setTimeout(() => _snapB(_iB + 1), _msB));
-                  setTimeout(() => { try { if (fxRt.node && fxRt.node.port) fxRt.node.port.removeEventListener('message', _wlB); } catch (e) {} }, 1600);
-                }
               }
             } else {
               fxRtStop();
@@ -22090,7 +22035,7 @@ const App = () => {
         const _contentNow = (startOffsetTimeRef.current || 0) + (_c.currentTime - (startAudioTimeRef.current || _c.currentTime));
         startOffsetTimeRef.current = _contentNow;
         startAudioTimeRef.current = _c.currentTime;
-        if (_pa !== null) fxRt.processedAnchor = _pa - Math.round(fxRt.latencyTotal || 0);
+        if (_pa !== null) fxRt.processedAnchor = _pa - FX_RT_WET_LAG_SAMPLES;
         fxRtWarmPlayHold = false;
       } else {
         // (M22) rebase wall — khi khong OFF-giua-play (warm tu stop), off/at la
@@ -25268,7 +25213,7 @@ const App = () => {
         if (fxRt && fxRt.active && typeof fxRt.processedSamples === 'number' && fxRt.processedAnchor != null) {
           _posSamples = Math.max(
             Math.floor(startOffsetTimeRef.current * (_pctx.sampleRate || 44100)),
-            Math.floor(startOffsetTimeRef.current * (_pctx.sampleRate || 44100) + (fxRt.processedSamples - fxRt.processedAnchor - (fxRt.latencyTotal || 0)))
+            Math.floor(startOffsetTimeRef.current * (_pctx.sampleRate || 44100) + (fxRt.processedSamples - fxRt.processedAnchor - FX_RT_WET_LAG_SAMPLES))
           );
         } else {
           const _elapsed = _pctx.currentTime - (startAudioTimeRef.current || _pctx.currentTime);
@@ -25534,7 +25479,7 @@ const App = () => {
           const context = getAudioContext();
           let _ph = startOffsetTimeRef.current + (context.currentTime - startAudioTimeRef.current);
           if (fxRt && fxRt.active && typeof fxRt.processedSamples === 'number' && fxRt.processedAnchor != null) {
-            _ph = startOffsetTimeRef.current + (fxRt.processedSamples - fxRt.processedAnchor - (fxRt.latencyTotal || 0)) / (context.sampleRate || 44100);
+            _ph = startOffsetTimeRef.current + (fxRt.processedSamples - fxRt.processedAnchor - FX_RT_WET_LAG_SAMPLES) / (context.sampleRate || 44100);
           }
           let _local = _ph;
           const _itemInfo = getPianoRollItemInfo(st);
@@ -25562,7 +25507,7 @@ const App = () => {
       let wallTime = startOffsetTimeRef.current + elapsed;
       const bufferPos = startBufferOffsetRef.current + elapsed * speedFactor;
       if (fxRt && fxRt.active && typeof fxRt.processedSamples === 'number' && fxRt.processedAnchor != null) {
-        wallTime = startOffsetTimeRef.current + (fxRt.processedSamples - fxRt.processedAnchor - (fxRt.latencyTotal || 0)) / (context.sampleRate || 44100);
+        wallTime = startOffsetTimeRef.current + (fxRt.processedSamples - fxRt.processedAnchor - FX_RT_WET_LAG_SAMPLES) / (context.sampleRate || 44100);
       }
 
       // Loop sub-tab selection (bufferPos is buffer-time)
@@ -25640,7 +25585,7 @@ const App = () => {
     const _playheadSec = (_fxRtSeekFreeze && fxRt && fxRt.active)
       ? startOffsetTimeRef.current
       : ((fxRt && fxRt.active && typeof fxRt.processedSamples === 'number' && fxRt.processedAnchor != null)
-          ? Math.max(startOffsetTimeRef.current, startOffsetTimeRef.current + (fxRt.processedSamples - fxRt.processedAnchor - (fxRt.latencyTotal || 0)) / (context.sampleRate || 44100))
+          ? Math.max(startOffsetTimeRef.current, startOffsetTimeRef.current + (fxRt.processedSamples - fxRt.processedAnchor - FX_RT_WET_LAG_SAMPLES) / (context.sampleRate || 44100))
           : updatedTime);
 
     // Selection Loop - LOOP_MAKER.md + LOOP_EDITOR_2.md §4.2