Two narrow repairs for #97948 symptom B (large-session rotation aborts with
'Compression lease lost before publication' / session_split_failed, then the
next turn re-runs the identical doomed compression):
1. publish_compression_child gains require_lease_refresh: the lease is
extended inside the same transaction as the expiry check (same conn, no
TOCTOU), giving a worker whose refresher thread died from transient DB
failures one final chance to keep its completed work.
2. A failed compression split now records a 60s failure cooldown, so the
next turn cannot immediately re-trigger the same compression.
Salvaged from #98137 (author: vsd2807). The timeout-reconciliation half of
that PR is NOT carried: it has a blocking review (runtime sid vs persisted
session_key, one-shot check cannot observe a 6-minute commit, no identity
projection) and needs a redesign.
087cc49a26