Fixes transcription failures with MAI Transcribe 2 and other OpenRouter models that reject M4A uploads with a generic provider error.
- MAI Transcribe 2 now receives WAV audio immediately.
- Other transcription models retry once with WAV when OpenRouter returns the opaque
Provider returned 400error. Explicit request, authentication, and rate-limit errors remain unchanged.
Requires TypeWhisper 1.5.0 or later.