fix: ScriptProcessorNode fallback + worklet process() logging

- ScriptProcessorNode fallback khi AudioWorkletNode fails
- Render trực tiếp trong onaudioprocess callback, không cần setInterval
- Worklet log peak + queue depth mỗi 50 process() calls
- Log audioCtx state + sampleRate khi init

app/static/js/services/soundfontPlayer.js

@@ -66,10 +66,15 @@
                     _audioCtx = audioContext;
                     if (_audioCtx.state === 'suspended') await _audioCtx.resume();
 
+                    console.log("[SonicSF] AudioCtx state:", _audioCtx.state, "sampleRate:", _audioCtx.sampleRate);
+
+                    var _useScriptNode = false;
                     try {
                         await _audioCtx.audioWorklet.addModule('/static/js/worklets/fluidsynth-bridge.js');
+                        console.log("[SonicSF] Worklet registered OK");
                     } catch (e) {
-                        console.warn("[SonicSF] Worklet reg failed:", e);
+                        console.warn("[SonicSF] Worklet reg failed, fallback ScriptProcessorNode:", e);
+                        _useScriptNode = true;
                     }
 
                     console.log("[SonicSF] Initializing FluidSynth WASM Engine...");
@@ -106,13 +111,43 @@
 
                     try { _fluidModule.FS.mkdir('/soundfonts'); } catch (e) {}
 
-                    _workletNode = new AudioWorkletNode(_audioCtx, 'fluidsynth-bridge');
-
                     _leftBufPtr = _fluidModule._malloc(RENDER_BLOCK * 4);
                     _rightBufPtr = _fluidModule._malloc(RENDER_BLOCK * 4);
 
-                    _workletNode.connect(_audioCtx.destination);
+                    if (!_useScriptNode) {
-                    _startRenderLoop();
+                        try {
+                            _workletNode = new AudioWorkletNode(_audioCtx, 'fluidsynth-bridge');
+                            _workletNode.connect(_audioCtx.destination);
+                            console.log("[SonicSF] AudioWorklet node connected");
+                            _startRenderLoop();
+                        } catch (e) {
+                            console.warn("[SonicSF] AudioWorkletNode failed:", e);
+                            _useScriptNode = true;
+                        }
+                    }
+                    if (_useScriptNode) {
+                        var spBufSz = 2048;
+                        var spn = _audioCtx.createScriptProcessor(spBufSz, 0, 2);
+                        var lp = _fluidModule._malloc(spBufSz * 4);
+                        var rp = _fluidModule._malloc(spBufSz * 4);
+                        spn.onaudioprocess = function (e) {
+                            var left = e.outputBuffer.getChannelData(0);
+                            var right = e.outputBuffer.getChannelData(1);
+                            var sz = left.length;
+                            try {
+                                _fluidModule._fluid_synth_write_float(_synthPtr, sz, lp, 0, 1, rp, 0, 1);
+                                var hf = _fluidModule.HEAPF32;
+                                var lpb = lp >> 2, rpb = rp >> 2;
+                                for (var si = 0; si < sz; si++) {
+                                    left[si] = hf[lpb + si];
+                                    right[si] = hf[rpb + si];
+                                }
+                            } catch (er) {}
+                        };
+                        spn.connect(_audioCtx.destination);
+                        _workletNode = spn;
+                        console.log("[SonicSF] ScriptProcessorNode fallback active (buf:", spBufSz, ")");
+                    }
 
                     _initialized = true;
                     console.log("[SonicSF] FluidSynth WASM Engine initialized.");

app/static/js/worklets/fluidsynth-bridge.js

@@ -3,6 +3,7 @@ class FluidSynthBridge extends AudioWorkletProcessor {
     super();
     this.leftQ = [];
     this.rightQ = [];
+    this.called = 0;
     this.port.onmessage = (e) => {
       const d = e.data;
       if (d.type === 'PCM') {
@@ -15,6 +16,7 @@ class FluidSynthBridge extends AudioWorkletProcessor {
   process(inputs, outputs) {
     const out = outputs[0];
     if (!out) return true;
+    this.called++;
     const len = out[0].length;
     const qL = this.leftQ;
     const qR = this.rightQ;
@@ -28,6 +30,14 @@ class FluidSynthBridge extends AudioWorkletProcessor {
       if (si >= qL[fi].length) { fi++; si = 0; }
     }
     if (fi > 0) { this.leftQ.splice(0, fi); this.rightQ.splice(0, fi); }
+    if (this.called % 50 === 0) {
+      var pk = 0;
+      for (var j = 0; j < len; j++) {
+        var v = out[0][j] > 0 ? out[0][j] : -out[0][j];
+        if (v > pk) pk = v;
+      }
+      if (pk > 0) console.log('[FluidSynth:bridge] process #' + this.called + ' peak:' + pk.toFixed(6) + ' q:' + qL.length);
+    }
     return true;
   }
 }