feat(log): log authority is the fleet default — adopt-at-open, oracle-gated; plus the power-cut throw-site cures and the loud torn-record contract

THE DEFAULT FLIP (ruled on proven evidence — at-ack survived 301/301
acked-writes-through-power-cut in block-layer fault injection; deferred
tree authority demonstrably loses flush-covered acks): a brain with NO
stored authority artifact now ADOPTS LOG AUTHORITY AT OPEN. The oracle
gates the flip exactly as the guarded adoption path always did — curable
divergences baseline-backfilled, the flip lands ONLY on a green verdict —
and a brain that cannot verify STAYS tree-authoritative loudly, with the
refusal recorded on the switch artifact so subsequent opens are cheap.
config logAuthority: 'defer' is the explicit documented opt-out (no
automatic adoption; declared flush-window loss; adoptLogAuthority() flips
later). A stored artifact always wins. RELEASES.md carries the posture.

Two standing .fails debt pins FLIP TO HOLDING under the default: the
at-ack crash-survival gap and the ack-at-log durability target — both now
permanent asserted truths, not aspirations.

POWER-CUT THROW SITES (fault-injection findings, brainy-alone config):
- A manifest-listed-but-unloadable column segment QUARANTINES at
  discovery (loud once, counted always, quarantinedSegments() exposed for
  the heal) and the field serves its remaining segments DEGRADED — never
  a raw throw killing every query on the field. Real storage faults still
  propagate untouched.
- Torn generation artifacts (NaN/garbage in manifest or counter) DISCARD
  with narration at the store's open and recovery re-derives — plus a
  defensive finite-integer guard at the init consumer. Never a RangeError
  killing an open.

THE LOUD TORN-RECORD CONTRACT: an existing-but-unparseable stored record
now surfaces as a typed, counted TornRecordError on every entity-read
surface (including fifteen previously-blind per-item batch catches);
ENOENT stays clean-absent; artifact readers with designed absent-recovery
keep null-tolerance behind the loud floor. Disk corruption can no longer
read as silent data invisibility.

Suite migration: the default's pins inverted deliberately, generation
baselines made relative, quarantine-contract pins rewritten to the ruled
behavior.

Gates: tsc 0 · unit 2065/2065 (159 files) · integration 826 (93 files) ·
conformance 31/31 · kill-matrix 15/15 · torn-open guards 2/2.

RELEASES.md

@@ -37,6 +37,17 @@ The theme: **writes ack fast and honestly, startup adopts instead of rebuilding,
 every query path serves, announces, or refuses — never silently degrades.** Ships as
 one release together with the matching native accelerator version.
 
+**The storage-authority posture (the release's headline):** a NEW brain's default
+is **durable-at-ack log authority** — the generation log is the source of truth,
+every write acknowledgment is covered by a group-committed fsync, and crash
+recovery is a replay of the log (an acked write survives power loss, proven by
+fault-injection tests). An EXISTING brain adopts at its first open under 10.0.0,
+gated by a verification oracle: the log is replayed and diffed against stored
+truth record-by-record; curable gaps are backfilled; the brain flips only on a
+green verdict and a brain that cannot verify stays on the previous posture and
+says so loudly. The explicit opt-out is `logAuthority: 'defer'` in the config
+(no automatic adoption; flip later with `adoptLogAuthority()`).
+
 **Why a major:** the generation log gains write format v2 — new segments carry typed,
 versioned records with integrity seals. A 9.x build refuses a v2 segment with a clear
 version-naming error (never a misread), which means **a brain written by 10.x cannot