Cancel Job

Cancel/delete an indexing job.

Maps to POST /v1/index-stop/{job_id}

Behavior:

• If job is pending or running -> transition to cancelled
• If job is already completed/failed/cancelled -> return 200 with current state (idempotent)

Returns:

• job_id: The job identifier
• status: Current status after cancel attempt
• message: Human-readable description
• cancelled_at: Cancellation timestamp (RFC3339)

Authentication: Requires Bearer token in Authorization header