G3 deploy: mac dinh dung JUCE bridge + bundle juce_fx_bridge vao engine

app/core/fx_realtime.py

@@ -26,7 +26,7 @@ import uuid
 import numpy as np
 
 from app.config import settings
-from app.core.native_render import find_fx_bridge_exe
+from app.core.native_render import find_fx_bridge_exe, find_juce_fx_bridge_exe
 
 FXRT_MAGIC = 0x46585254
 FXRT_BLOCK = 256
@@ -164,9 +164,11 @@ class FxRealtimeSession:
 
     def _spawn(self):
         juce_exe = os.getenv("SF_JUCE_FX_BRIDGE_PATH", "").strip()
-        exe = juce_exe or find_fx_bridge_exe()
+        # G3: mặc định dùng JUCE bridge (latency graph thật + processed samples);
+        # fallback bridge cũ khi không có exe JUCE (regression an toàn).
+        exe = juce_exe or find_juce_fx_bridge_exe() or find_fx_bridge_exe()
         if not exe:
-            raise RuntimeError("Không tìm thấy fx_vst_bridge.exe")
+            raise RuntimeError("Không tìm thấy bridge exe (juce_fx_bridge / fx_vst_bridge)")
         job = {
             "sample_rate": self.sample_rate,
             "block_size": self.block_size,
@@ -176,7 +178,7 @@ class FxRealtimeSession:
         fd, self._job_path = tempfile.mkstemp(suffix=".json", prefix="fxrt_")
         with os.fdopen(fd, "w", encoding="utf-8") as f:
             json.dump(job, f)
-        if juce_exe:
+        if os.path.basename(exe).lower().startswith("juce_fx_bridge"):
             cmd = [exe, "--juce-fx", self._job_path, "--shm", self.name,
                    "--parent", str(os.getpid())]
         else: