fix: Lỗi không có âm thanh - quay lại ScriptProcessor vĩnh viễn (worklet push-model bị nghẽn main thread -> câm)

app/static/js/services/soundfontPlayer.js

@@ -86,16 +86,18 @@
 
                     console.log("[SonicSF] AudioCtx state:", _audioCtx.state, "sampleRate:", _audioCtx.sampleRate);
 
-                    // Use the AudioWorklet (fluidsynth-bridge) — ScriptProcessor
-                    // is deprecated and logs a console warning. The worklet is
-                    // now mono-safe (handles 1/2/N channel outputs) and the node
-                    // is forced stereo, and the URL is cache-busted so the fixed
-                    // module always loads. Falls back to ScriptProcessor if the
-                    // worklet cannot be created (older browsers).
-                    var _useScriptNode = false;
+                    // ── Renderer selection ──
+                    // ScriptProcessor is the default and FINAL choice: it is
+                    // pull-based (onaudioprocess is invoked by the audio thread),
+                    // so it cannot starve when the main thread is busy (font
+                    // loading, WASM decode, UI). The AudioWorklet push model
+                    // (setInterval on the main thread) starves under load and
+                    // produces SILENCE on this machine — repeatedly confirmed.
+                    // The deprecation console warning is purely cosmetic.
+                    var _useScriptNode = true;
                     try {
-                        await _audioCtx.audioWorklet.addModule('/static/js/worklets/fluidsynth-bridge.js?v=202608031315');
-                        console.log("[SonicSF] Worklet registered OK");
+                        await _audioCtx.audioWorklet.addModule('/static/js/worklets/fluidsynth-bridge.js?v=202608031240');
+                        console.log("[SonicSF] Worklet registered OK (unused)");
                     } catch (e) {
                         console.warn("[SonicSF] Worklet reg failed:", e);
                     }