N-06: export one idempotency-key authority from mutation-intent.ts and use it
in the V2 client. A caller-supplied key is validated before credentials, timers
and fetch, and an invalid value is rejected as VALIDATION_REJECTED /
IDEMPOTENCY_KEY_INVALID rather than trimmed, regenerated or dropped, so a keyed
command can no longer replay while sending no key.
N-07: bound the legacy credential wait by the existing attempt controller,
which already carries the total deadline and the caller signal, so a
non-cooperative owner cannot hold the request open and no extra timer is
introduced. The owner receives the operation context, and the failure follows
ownership: deadline to REQUEST_TIMEOUT, caller to REQUEST_ABORTED, and only a
genuine rejection to AUTH_INTEGRATION_FAILURE. None of these paths fetch.
N-08: readBoundedJson delegates to the common bounded reader, so cancel and
releaseLock throws stay isolated inside the closed result, and the V2
content-type mismatch now cancels the response body.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
