feat(ui): add GUI button beside Synth button to reopen VSTi editor — track strip + piano-roll toolbar; sends bridge OPEN_GUI via router channel

app/static/js/app.jsx

@@ -9840,7 +9840,15 @@ const beatSec = 60.0 / (parseInt(bpm) || 120);
       onClick: () => onInstrumentSelect && onInstrumentSelect(st.trackId),
       title: st.instrumentName || "Synth",
       className: `px-1.5 py-0.5 text-[10px] rounded font-mono font-bold border transition flex items-center gap-0.5 max-w-[70px] ${st.instrumentName ? 'bg-violet-900 text-violet-300 border-violet-700' : 'bg-zinc-800 text-zinc-500 border-transparent hover:text-zinc-300'}`
-    }, React.createElement("i", { "data-lucide": "music", className: "w-3 h-3 shrink-0" }), React.createElement("span", { className: "truncate text-[9px]" }, activeParentTrackName ? ('(' + activeParentTrackName + ') ' + (st.instrumentName || 'Synth')) : (st.instrumentName || 'Synth'))), React.createElement("div", {
+    }, React.createElement("i", { "data-lucide": "music", className: "w-3 h-3 shrink-0" }), React.createElement("span", { className: "truncate text-[9px]" }, activeParentTrackName ? ('(' + activeParentTrackName + ') ' + (st.instrumentName || 'Synth')) : (st.instrumentName || 'Synth'))), (st.instrumentId && typeof st.instrumentId === 'string' && !st.instrumentId.startsWith('sf_') ? React.createElement("button", {
+      onClick: () => {
+        if (!window.SonicMidiRouter || !window.SonicMidiRouter.isBridgeActive() || !window.NativeBridgeService) return;
+        const bch = window.SonicMidiRouter.allocateChannel(st.trackId, false);
+        window.NativeBridgeService.openNativeGUI(st.instrumentId, bch);
+      },
+      title: "Mở lại GUI VSTi",
+      className: "px-1.5 py-0.5 text-[10px] rounded font-mono font-bold border transition flex items-center gap-0.5 bg-zinc-800 text-violet-300 border-violet-800 hover:bg-violet-900/40"
+    }, React.createElement("i", { "data-lucide": "sliders-horizontal", className: "w-3 h-3 shrink-0" }), React.createElement("span", { className: "truncate text-[9px]" }, "GUI")) : null), React.createElement("div", {
       className: "flex items-center gap-1 ml-1 text-xs"
     }, React.createElement("span", { className: "text-zinc-500" }, "AI:"), React.createElement("input", {
       type: "number", value: aiBarStart, onChange: e => setAiBarStart(parseInt(e.target.value) || 0),
@@ -29736,7 +29744,16 @@ STRICT CONSTRAINTS:
       }, /*#__PURE__*/React.createElement("i", {
         "data-lucide": "music",
         className: "w-3 h-3"
-      })), /*#__PURE__*/React.createElement("span", { className: "truncate text-[10px]" }, track.instrumentName || track.instrumentId || "Synth"), /*#__PURE__*/React.createElement("i", { "data-lucide": "chevron-down", className: "w-3 h-3 shrink-0" }))), /*#__PURE__*/React.createElement("div", {
+      })), /*#__PURE__*/React.createElement("span", { className: "truncate text-[10px]" }, track.instrumentName || track.instrumentId || "Synth"), /*#__PURE__*/React.createElement("i", { "data-lucide": "chevron-down", className: "w-3 h-3 shrink-0" }))), (track.instrumentId && typeof track.instrumentId === 'string' && !track.instrumentId.startsWith('sf_') ? /*#__PURE__*/React.createElement("button", {
+        onClick: (e) => {
+          e.stopPropagation();
+          if (!window.SonicMidiRouter || !window.SonicMidiRouter.isBridgeActive() || !window.NativeBridgeService) return;
+          const bch = window.SonicMidiRouter.allocateChannel(track.id, false);
+          window.NativeBridgeService.openNativeGUI(track.instrumentId, bch);
+        },
+        title: "Mở lại GUI VSTi",
+        className: "px-2 py-1 bg-zinc-800 hover:bg-zinc-700 text-violet-300 border border-violet-800 rounded text-xs font-bold flex items-center gap-1"
+      }, /*#__PURE__*/React.createElement("i", { "data-lucide": "sliders-horizontal", className: "w-3 h-3" }), /*#__PURE__*/React.createElement("span", { className: "truncate text-[10px]" }, "GUI")) : null), /*#__PURE__*/React.createElement("div", {
         onMouseDown: e => handleTrackResizeMouseDown(e, track.id),
         className: "absolute bottom-0 left-0 right-0 h-1 cursor-ns-resize z-30 hover:bg-cyan-500/50 transition-colors",
         onClick: e => e.stopPropagation()

app/templates/index.html

@@ -50,7 +50,7 @@
     <script src="/static/js/services/midiExtractor.js?v=202607281052"></script>
     <script src="/static/js/services/promptTemplateManager.js?v=202607281039"></script>
     <script src="/static/js/services/undoRedoEngine.js?v=202607290941"></script>
-    <script src="/static/js/app.precompiled.js?v=202608121700" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608121800" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {