Codex gate CORE: the exact-empty sentinel only suppressed restore for a bit-empty
cleared sidecar. If the user cleared, then sent ONE post-clear message, and the
stale pre-clear .json.bak still existed (unlink failed), recovery saw
bak_count>live_count and RESTORED the pre-clear transcript on top of the new
message. Added _live_supersedes_backup_by_clear_generation: suppress restore when
the live sidecar carries a clear_generation the backup lacks AND has a non-empty
transcript AND still shows the clear boundary reset (watermark==boundary==0.0).
Scoped to non-empty live so empty clear-shaped sidecars keep their existing
recovery semantics (active/pending/partial variants still restore). Fails open on
unreadable/partial reads. +2 regression tests (post-clear-message not restored;
post-clear-after-real-compaction still restores).
nesquena-hermes
bb818a56ba