Add WhisperKit Local Server with audio transcription and translation APIs (#348)

## Summary

Adds a complete WhisperKit Local Server with OpenAI API compliance for audio transcription and translation. Including client examples in Python, Swift, and shell scripts.

## Key Features

- **Local Server**: OpenAI-compatible `/v1/audio/transcriptions` and `/v1/audio/translations` endpoints
- **Transcription Streaming**: Server-sent events as files get transcribed
- **Response Formats**: Support for `json`, `verbose_json`
- **Timestamp Granularities**: Word-level and segment-level timestamps
- **Client Examples**: Python, Swift, and Bash with curl

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Co-authored-by: ZachNagengast <znagengast@gmail.com>