fix(fx): realtime VST ngắt quãng khi mở MASTERING PANEL + PWR master không ảnh hưởng âm; pacing WS input/output, gate fxRt theo masterConnected, worklet cap 32

native_bridge/include/FxRealtimeIPC.h

@@ -0,0 +1,39 @@
+// native_bridge/include/FxRealtimeIPC.h
+// SHM layout cho fx_vst_bridge --realtime-fx (VST FX xử lý realtime, cloud-FX
+// loop): engine (Python) tạo mapping, bridge mở và chạy vòng lặp audio.
+// Tất cả field u32/float (4-byte) — KHÔNG padding — mirror chính xác bằng
+// ctypes trong app/core/fx_realtime.py.
+#pragma once
+#include <cstdint>
+
+#define FXRT_MAGIC 0x46585254u      // "FXRT"
+#define FXRT_BLOCK 256
+#define FXRT_IN_SLOTS 4             // engine -> bridge
+#define FXRT_OUT_SLOTS 8            // bridge -> engine
+#define FXRT_STATE_STARTING 0
+#define FXRT_STATE_READY 1
+#define FXRT_STATE_ERROR 2
+
+// Header 48 bytes (12 u32) — giữ thứ tự khớp fx_realtime.py.
+struct FxRealtimeHeader {
+    volatile uint32_t magic;
+    volatile uint32_t state;
+    uint32_t sampleRate;
+    uint32_t blockSize;
+    volatile uint32_t running;      // engine set 0 → bridge thoát
+    volatile uint32_t heartbeat;    // bridge tăng mỗi 100ms (watchdog)
+    volatile uint32_t inWrite;      // producer: engine
+    volatile uint32_t inRead;       // consumer: bridge
+    uint32_t inSlots;
+    volatile uint32_t outWrite;     // producer: bridge
+    volatile uint32_t outRead;      // consumer: engine
+    uint32_t outSlots;
+};
+
+struct FxRealtimeIPC {
+    FxRealtimeHeader h;
+    float inL[FXRT_IN_SLOTS][FXRT_BLOCK];
+    float inR[FXRT_IN_SLOTS][FXRT_BLOCK];
+    float outL[FXRT_OUT_SLOTS][FXRT_BLOCK];
+    float outR[FXRT_OUT_SLOTS][FXRT_BLOCK];
+};

native_bridge/include/RenderFxJob.h

@@ -81,3 +81,8 @@ private:
 };
 
 #endif // RENDER_FX_JOB_H
+// Realtime SHM FX loop (fx_vst_bridge --realtime-fx): engine (Python) tạo
+// mapping FxRealtimeIPC, bridge mở, đọc input ring, xử lý qua RealtimeFxChain,
+// ghi output ring. Thoát khi running==0 hoặc parent chết.
+int run_realtime_fx_loop(const std::string& jobPath, const std::string& shmName,
+                         uint32_t parentPid);