Fetch fares for a specific flight solution and stream them as Server-Sent Events. Requires a Mercury UUID for searchSolutionId (the value emitted as id by POST /v1/flights/search); unknown or expired identifiers return 410 OFFER_EXPIRED. Each data: event is a JSON-encoded fare object whose fareId is a canonical Mercury UUID. The stream ends with event: done.

Frame vocabulary (event: names on this stream):

• solution — one priced flight fare.
• done — terminal frame; the stream is exhausted (data: {}).
• error — terminal frame on failure; data: {"code": ..., "message": ...}.