SELF-ENGINE-LIFECYCLE-SPRINT + BRAINY-PROD-LATENCY-TRIAD, the four asks:
(a) brain.flush() persists aggregation state stamped at the committed
generation. The stamp used to advance only at close(), so a long-lived
writer that flushes but never closes — the primary production shape —
left every write window behind the stamp, and ANY unclean exit forced a
whole-store backfill walk (per-entity work, measured >60s and
door-starving on a 9k-row production brain) on the first stats call.
(b) BEHIND-stamp adoption becomes adopt + INCREMENTAL CATCH-UP: the exact
missing window (stamp, committed] resolves its affected-id set from the
fact log and reconciles each entity with time-travel before/after reads
(asOf at both window bounds) through the same delta algebra the live
hooks use — cost bounded by writes since the last flush, never store
size, and exact under interleaving because reconciliation targets the
FIXED window end while later writes chain through hooks. Oversized
windows (>5000 affected) and unreadable windows demote to the announced
rescan — never a silent partial serve.
(c) The native provider's parallel rebuildAggregate — on the contract since
8.x but never invoked anywhere — is now the backfill walk's preferred
door: one call per aggregate with source-matched entities, replacing
the per-entity FFI stream.
(d) A delete whose before-image is unavailable can no longer SKIP the
aggregation hook silently (counts drifted upward forever): both delete
paths (remove() and transact) flag an exact rescan, loudly.
Pins: integration (flush stamp; unclean-exit reopen → exact counts through
an add + group-move + delete window with the walk spy proving ZERO
whole-store walks) + unit (provider rebuild invoked once with filtered
entities; flagAllForRescan; reconcile delta algebra). Gates: unit 1913/1913
· integration 760 · conformance 27/27.
