api.releaseIdempotencyKey()
Deletes an idempotency key unconditionally, allowing another attempt to acquire it.
Notes:
- This does not roll back business effects and does not check an ownership token.
- Release for retry only when no business effect occurred (or rollback is confirmed), and the key still belongs to this attempt. Retain it when the outcome is uncertain.
- Never release in a generic catch/finally merely because processing threw or timed out: a partial effect or committed operation could then be executed twice.
- A late cleanup after TTL expiry may delete a key acquired by another worker.
- Unavailable with
readOnly: true(throws an error).

