fix: nut Synth tren TCP khong hien danh sach VSTi da scan (ban 1.1.5)

- Nut Synth TCP goi openInstrumentSelector (modal 'Select Instrument')
  nhung modal chi co category SoundFont + GM - khong co muc VST (muc VST
  chi ton tai o dropdown MixerStrip). Them 'VST Instruments' vao sidebar
  trai modal: list instrumentSelectorData.vst_instruments (listPlugins),
  click -> setTrackInstrumentWithUndo(trackId, v.id, v.name) + dong modal.
- _scan_vst_in_dirs + /scan: phat hien ca FOLDER ten X.vst3 (Windows VST3
  = folder chua X.vst3.dll) - truoc day chi scan file.
- Ghi chu: pedalboard (engine VST) la headless - KHONG mo duoc GUI goc cua
  plugin; danh sach + chon la co che chon nhac cu kha thi.

Verify engine frozen: /plugins/available tra ['PadMachine','UltraSynth']
(ca file va folder .vst3); /scan dong bo; test_plugin_api 3 passed.

app/static/js/app.jsx

@@ -29876,7 +29876,14 @@ STRICT CONSTRAINTS:
               },
               className: "w-full text-left px-3 py-2 text-sm rounded " + (selectedSoundFontId === sfId ? "bg-amber-700 text-white" : "bg-zinc-800 hover:bg-zinc-700 text-zinc-300")
             }, sfName);
-          })
+          }),
+          // ── VST Instruments (scanned bởi Plugin Manager) ──
+          (instrumentSelectorData?.vst_instruments?.length > 0) && /*#__PURE__*/React.createElement("div", { className: "mt-3 text-[10px] text-zinc-500 uppercase font-bold px-1 flex items-center gap-1" }, /*#__PURE__*/React.createElement("i", { "data-lucide": "cpu", className: "w-3 h-3 text-violet-400" }), "VST Instruments"),
+          (instrumentSelectorData?.vst_instruments || []).map(v => /*#__PURE__*/React.createElement("button", {
+            key: 'vst_modal_' + (v.id || v.name),
+            onClick: () => { setTrackInstrumentWithUndo(instrumentSelectorTrackId, v.id, v.name || v.id); closeInstrumentSelector(); },
+            className: "w-full text-left px-3 py-2 text-sm rounded bg-zinc-800 hover:bg-violet-800 text-zinc-300 flex items-center justify-between gap-2"
+          }, /*#__PURE__*/React.createElement("span", { className: "truncate" }, v.name || v.id), /*#__PURE__*/React.createElement("span", { className: "text-[9px] text-cyan-400 shrink-0" }, v.type || "VST")))
         ),
         /*#__PURE__*/React.createElement("div", { className: "flex-1 overflow-y-auto space-y-0.5" },
           /*#__PURE__*/React.createElement("button", {