faster-whisper's transcribe() was handed the path of a still-open NamedTemporaryFile; on Windows the open handle is exclusive, so PyAV's reopen failed with EACCES and local STT was broken. Switch to delete=False, close before transcribing, and unlink in a finally. The write is wrapped in the file's context manager so the handle closes even if write() raises, and unlink failures are logged at debug.
