Two tests asserted resolve+reload events but acquired the lease
immediately (no wait). After gating the reload behind _lease_waited,
these tests must simulate a contended wait via on_wait(0.0) to
exercise the resolve+reload path.
Refresh-loss interrupt is cooperative, so a stalled writer could still flush after another process reclaimed the conversation. Carry the holder into append_message / append_messages_batch and reject the write in the same SQLite transaction when the lease row is missing, expired, or owned by someone else.
Presence-only _delegate_from/_branched_from checks stopped the lease walk on
continuations that copied a delegate's model_config, so the first refresh
after rotation missed the parent-key lease and hard-interrupted. A failed
get_session probe also skipped acquire entirely. Walk the lineage inside
the write transaction and treat a probe error as contended, not a fresh
session.
Honor interrupts while waiting for admission, stop the turn when refresh
loses the lease, poll once per second under contention, and test dead-PID
reclaim.
fangliquanflq