V45.39: fix SERVER OFFLINE lau + UI load cham - engine ghi port file (engine_port.txt), UI bootstrap doc port engine cua chinh no (get_engine_port) + timeout/retry 60s, health poll self-heal reload, khong taskkill /IM daw_engine (giet engine instance khac), /api/v1/plugins/available chay scan trong threadpool (khong chan event loop -> /health het timeout)

desktop_engine.py

@@ -116,6 +116,17 @@ def main():
     port = _pick_port()
     os.environ["SF_PORT"] = str(port)
 
+    # Announce port to Tauri shell: UI bootstrap đọc %APPDATA%/SonicForgeDAW/
+    # engine_port.txt (qua lệnh get_engine_port) để kết nối ĐÚNG engine của
+    # chính nó thay vì quét port — quét 8000-8010 có thể dính engine của
+    # instance khác (2 app chạy cùng lúc) → UI mất server khi instance đó tắt.
+    try:
+        port_file = os.path.join(os.path.dirname(log_dir), "engine_port.txt")
+        with open(port_file, "w", encoding="utf-8") as f:
+            f.write(str(port))
+    except OSError:
+        pass
+
     # Log ra file — khi dong goi console=False, stdout khong nhin thay duoc.
     try:
         logging.basicConfig(