Lock and remove expired terminal runs plus dependent events/attempts.
Lightweight aggregate health; no job payloads.
Insert-if-absent; returns the actual locked record, including concurrent inserts.
Current repository time, obtained after any blocking lock acquisition.
Optionallock: booleanLock one ready supported run OR any expired owner; skip rows locked elsewhere.
Transactional storage primitives for adapter authors. Locked rows remain locked until atomic() commits. Reads/writes must be detached. Implementations must roll back every write on callback failure.