Audit v2 silent breakage / standing rule violation
(feedback_offline_first_for_server_writes): RequestsRepository.cancel
was direct REST with no queue fallback. Tap cancel offline and the
user's intent vanishes.
Now mirrors the unflag / appendTrack / requestCreate pattern: REST on
the happy path, MutationKind.REQUEST_CANCEL enqueued on IOException.
Replayer's existing AuthStore.sessionCookie trigger drains it on the
next signed-in transition.
Repository signature changed from `suspend fun cancel(id): RequestRef`
to `Pair<CancelOutcome, RequestRef?>` so callers can distinguish
synced vs queued (RequestsViewModel ignores the distinction for now;
optimistic removal already reflects the user's intent and the
post-replay refresh surfaces the canonical row).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen
29c676fcf8