fix: add timeout to subprocess.run() and proc.wait() calls

subprocess.run() and proc.wait() without timeout can hang indefinitely
if the child process becomes unresponsive. This blocks the calling
thread forever.

Fixed locations:
- tools/transcription_tools.py: ffmpeg conversion (timeout=300) and
  user-configured STT commands with shell=True (timeout=300)
- gateway/run.py: helper script proc.wait() (timeout=3600)

Not fixed:
- agent/anthropic_adapter.py: interactive 'claude setup-token' —
  user-driven, timeout would be inappropriate

gateway/run.py

@@ -15126,7 +15126,7 @@ class GatewayRunner:
                     env["PYTHONUNBUFFERED"] = "1"
                     with open(output_path, "wb") as f:
                         proc = subprocess.Popen(cmd, stdout=f, stderr=subprocess.STDOUT, env=env)
-                        rc = proc.wait()
+                        rc = proc.wait(timeout=3600)
                     with open(exit_code_path, "w") as f:
                         f.write(str(rc))
                     """

tools/transcription_tools.py

@@ -1186,7 +1186,7 @@ def _prepare_local_audio(file_path: str, work_dir: str) -> tuple[Optional[str],
     command = [ffmpeg, "-y", "-i", file_path, converted_path]
 
     try:
-        subprocess.run(command, check=True, capture_output=True, text=True)
+        subprocess.run(command, check=True, capture_output=True, text=True, timeout=300)
         return converted_path, None
     except subprocess.CalledProcessError as e:
         details = e.stderr.strip() or e.stdout.strip() or str(e)
@@ -1229,9 +1229,9 @@ def _transcribe_local_command(file_path: str, model_name: str) -> Dict[str, Any]
             # User-provided templates (env var) may contain shell syntax; auto-detected commands are safe for list mode.
             use_shell = bool(os.getenv(LOCAL_STT_COMMAND_ENV, "").strip())
             if use_shell:
-                subprocess.run(command, shell=True, check=True, capture_output=True, text=True)
+                subprocess.run(command, shell=True, check=True, capture_output=True, text=True, timeout=300)
             else:
-                subprocess.run(shlex.split(command), check=True, capture_output=True, text=True)
+                subprocess.run(shlex.split(command), check=True, capture_output=True, text=True, timeout=300)
             
 
             txt_files = sorted(Path(output_dir).glob("*.txt"))