The guard also recognizes IDEMPOTENT_START_UNSUPPORTED keyed admission
(503) and malformed reservation input (400,
INVALID_START_IDEMPOTENCY_REQUEST).
Unsupported wiring remains in this guard because the keyed request is
intentionally refused at admission instead of being executed without its
exactly-once guarantee. StartReservationUnreadableError is deliberately
outside it: unreadable storage is an integrity or availability failure, not
a reservation decision, and propagates through the shared DoStatusError
renderer with IDEMPOTENT_START_UNREADABLE and its 503 status. A false
answer never permits an unkeyed start: a StartReservationUnreadableError
must still propagate as 503.
Recognize the five reservation-decision refusals:
IDEMPOTENT_START_OWNER_MISMATCH(403)IDEMPOTENT_START_TARGET_MISMATCH(409)IDEMPOTENT_START_PENDING(503)IDEMPOTENT_START_UNRESOLVABLE(409)IDEMPOTENT_START_ALREADY_SETTLED(409)The guard also recognizes
IDEMPOTENT_START_UNSUPPORTEDkeyed admission (503) and malformed reservation input (400,INVALID_START_IDEMPOTENCY_REQUEST).Unsupported wiring remains in this guard because the keyed request is intentionally refused at admission instead of being executed without its exactly-once guarantee.
StartReservationUnreadableErroris deliberately outside it: unreadable storage is an integrity or availability failure, not a reservation decision, and propagates through the sharedDoStatusErrorrenderer withIDEMPOTENT_START_UNREADABLEand its 503 status. A false answer never permits an unkeyed start: aStartReservationUnreadableErrormust still propagate as 503.