fix(exit): taskkill rieng tung process — kill het plugin_host/fx_vst_bridge khi thoat app (truoc day /IM gop chi chay lenh dau); CREATE_NO_WINDOW cho moi subprocess engine (het terminal chớp chớp)

app/api/v1/plugins.py

@@ -419,6 +419,7 @@ def _pick_dir_native_engine() -> Optional[str]:
             r = subprocess.run(
                 ["powershell", "-NoProfile", "-STA", "-Command", ps],
                 capture_output=True, text=True, timeout=PICK_DIR_TIMEOUT,
+                creationflags=subprocess.CREATE_NO_WINDOW,
             )
             return r.stdout.strip() or None
         except Exception:
@@ -798,7 +799,8 @@ async def open_in_carla(req: OpenInCarlaRequest, current_user: dict = Depends(ge
         cmd.append(carxs_path)
     try:
         cwd = os.path.dirname(carla) or None
-        proc = subprocess.Popen(cmd, cwd=cwd, close_fds=os.name != "nt")
+        proc = subprocess.Popen(cmd, cwd=cwd, close_fds=os.name != "nt",
+                                creationflags=subprocess.CREATE_NO_WINDOW if os.name == "nt" else 0)
         _register_carla_process(proc)
         return {
             "success": True,
@@ -1778,7 +1780,8 @@ def _running_sonicforge_pids() -> list:
         out = subprocess.run(
             ["powershell", "-NoProfile", "-Command",
              "Get-Process sonicforge-daw,daw_engine -ErrorAction SilentlyContinue | Select-Object -ExpandProperty Id"],
-            capture_output=True, text=True, timeout=10).stdout
+            capture_output=True, text=True, timeout=10,
+            creationflags=subprocess.CREATE_NO_WINDOW).stdout
         for line in out.splitlines():
             line = line.strip()
             if line.isdigit():