Mint a live transcription handshake token

Mint the short-lived token that opens a live transcription streaming connection for the calling session.

The token is scoped to live transcription only. It is rejected anywhere else in the API, so it cannot stand in for an access token.

This endpoint takes no request body. The response carries the token and the number of seconds it stays valid for.

Rate limit

This endpoint is limited to 5 requests per 60 seconds per IP address. Going over returns 429 with a plain text body, so mint one token per session and reuse it until it expires.