Use the non-mutating dedupe-cache contract when checking unaccepted Telegram updates. Preserve active handler and completed-update deduplication while allowing a real update to be accepted after repeated handler skip probes.
Fixes#105192
The retention bound, claim lease default, and liveness options type were
exported only for tests, which fails the dead-export gate. Tests pin the
policy literals locally instead.
Refs #107246
Telegram update ids are global across chats, but the update tracker rejected
any id at or below its single high-water mark. When one lane was delayed
while other lanes completed newer ids, the delayed durable-spool replay was
rejected as accepted-watermark and tombstoned without dispatch - silent
message loss. The tracker now rejects only restored-offset ids and exact ids
it already accepted, with the accepted-id set pruned at the persisted offset
plus a bounded retention window; the startup-only floor-replay special case
is deleted.
Refs #107246
Peter Steinberger