FIX: (1) MIDI item route CHỈ qua Carla bridge khi VSTi loaded (bỏ FluidSynth GM sai âm) ở mọi đường playback + ghosts; (2) updateSfRouting sync route gains nhánh gainNode + ensureMasteringRouting force-sync mọi node — preview MIDI keyboard qua mastering không cần bật/tắt power; (3) stopNote/panic dừng fallback oscillator theo channel:pitch — hết âm kêu liên tục sau khi thả phím

app/static/js/services/soundfontPlayer.js

@@ -21,6 +21,10 @@
     let _pendingNoteTimers = [];
     let _loadedFonts = {};
     let _activeOscillators = {};
+    // Fallback oscillator theo 'channel:pitch' — để stopNote/stopAll dừng được
+    // note khi thả phím (trước đây stopNote không dừng oscillator → âm kêu
+    // liên tục dù đã thả phím khi FluidSynth chưa sẵn sàng / font load fail).
+    let _activeOscillatorsByKey = {};
     let _gainNode = null;
     let _pendingOutputDestination = null;
     let _outputDestination = null; // cache đích route — dedupe swap dư giữa stream
@@ -479,6 +483,23 @@
             // Hủy note đang CHỜ LOAD soundfont (chưa noteon) — trước đây note
             // này vẫn bắn TRỄ sau khi thả phím → âm loop không dừng được.
             if (_pendingNoteOns[key]) delete _pendingNoteOns[key];
+            // ⚠️ FIX: dừng fallback oscillator theo 'channel:pitch' — trước đây
+            // stopNote chỉ noteoff FluidSynth, KHÔNG dừng oscillator (khi WASM
+            // chưa sẵn sàng / font load fail → _playNoteFallback) → âm kêu liên
+            // tục mặc dù đã thả phím (không xử lí noteoff).
+            var _oscIds = _activeOscillatorsByKey[key];
+            if (_oscIds && _oscIds.length) {
+                var _nowT = getCtx().currentTime;
+                _oscIds.slice().forEach(function (oid) {
+                    var entry = _activeOscillators[oid];
+                    if (entry) {
+                        try { entry.gain.gain.cancelScheduledValues(_nowT); entry.gain.gain.setValueAtTime(0, _nowT); } catch (e) {}
+                        try { entry.osc.stop(_nowT); } catch (e) {}
+                        delete _activeOscillators[oid];
+                    }
+                });
+                delete _activeOscillatorsByKey[key];
+            }
             if (_initialized && _fluidModule) {
                 var mappedChs = _activeNotes[key];
                 if (mappedChs === undefined) mappedChs = [channel];
@@ -711,6 +732,17 @@
                     for (var c = 0; c < 16; c++) _fluidModule._fluid_synth_all_notes_off(_synthPtr, c);
                 } catch (e) {}
             }
+            // Dừng fallback oscillator (FluidSynth chưa sẵn sàng / font fail)
+            try {
+                var _pctx = getCtx();
+                var _pnow = _pctx.currentTime;
+                Object.values(_activeOscillators).forEach(function (entry) {
+                    try { if (entry.gain) { entry.gain.gain.cancelScheduledValues(_pnow); entry.gain.gain.setValueAtTime(0, _pnow); } } catch (e) {}
+                    try { if (entry.osc) entry.osc.stop(_pnow); } catch (e) {}
+                });
+                Object.keys(_activeOscillators).forEach(function (k) { delete _activeOscillators[k]; });
+                _activeOscillatorsByKey = {};
+            } catch (e) {}
             _activeNotes = {};
         },
 
@@ -768,7 +800,20 @@
             osc.stop(stopAt);
             var oscId = note + '_' + Date.now() + '_' + Math.random();
             _activeOscillators[oscId] = { osc: osc, gain: noteGain };
-            setTimeout(function () { delete _activeOscillators[oscId]; }, (stopAt - ctx.currentTime) * 1000 + 100);
+            // Đăng ký theo 'channel:pitch' để stopNote dừng được khi thả phím
+            var oscKey = (channel !== undefined && channel >= 0 && channel < 16) ? (channel + ':' + note) : null;
+            if (oscKey) {
+                if (!_activeOscillatorsByKey[oscKey]) _activeOscillatorsByKey[oscKey] = [];
+                _activeOscillatorsByKey[oscKey].push(oscId);
+            }
+            setTimeout(function () {
+                delete _activeOscillators[oscId];
+                if (oscKey && _activeOscillatorsByKey[oscKey]) {
+                    var _oi = _activeOscillatorsByKey[oscKey].indexOf(oscId);
+                    if (_oi >= 0) _activeOscillatorsByKey[oscKey].splice(_oi, 1);
+                    if (_activeOscillatorsByKey[oscKey].length === 0) delete _activeOscillatorsByKey[oscKey];
+                }
+            }, (stopAt - ctx.currentTime) * 1000 + 100);
             return osc;
         },
 
@@ -805,6 +850,7 @@
                 } catch (e) {}
             });
             Object.keys(_activeOscillators).forEach(function (k) { delete _activeOscillators[k]; });
+            _activeOscillatorsByKey = {};
             _activeNotes = {};
         },