Follow-up on the salvaged #64511 commit:
- _automatic_compression_blocked() now refreshes durable guard state
(cooldown + fallback streak) when — and only when — the in-memory
snapshot says blocked, then re-evaluates. The should_compress()
pre-gates (preflight/turn paths) consult this before ever reaching
compress_context, and a stale fallback streak has no expiry timer, so
without a gate-level refresh a cleared durable row could never unblock
a prebound agent. The unblocked hot path pays no DB reads.
- A refresh that finds no durable cooldown row no longer clears a live
local cooldown whose DB persist FAILED (_cooldown_persist_failed):
an empty row is not evidence another agent cleared it, and honouring
it would reopen the #11529 thrash window. A successful durable
round-trip (record or read) makes the DB authoritative again.
- Guard tests for both directions (red on the pre-fix code), including
a hot-path test asserting the unblocked gate never touches the DB.
1093263aa6