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.

tests/unit/db/bounded-chains.test.ts

@@ -477,14 +477,17 @@ describe('materializeAtGeneration — bounded & deadlock-free (GA #33)', () => {
     const store = (brain as any).generationStore
 
     const N = 400
+    // Relative, not absolute: under the adopt-at-open default the open-time
+    // baseline backfill takes a generation of its own, so the first add is
+    // NOT generation 1 — pin the deep generation to the first add's commit.
+    let deepGen = 0
     for (let i = 0; i < N; i++) {
       await brain.add({ data: `doc ${i}`, type: NounType.Document, subtype: 'note', metadata: { i }, vector: VEC })
+      if (i === 0) deepGen = brain.generation()
     }
     const R = brain.generation() // ≈ N (each add is its own generation)
     expect(R).toBeGreaterThanOrEqual(N)
 
-    const deepGen = 1
-
     // Count getDelta invocations during the materialize.
     const realGetDelta = store.getDelta.bind(store)
     let getDeltaCalls = 0
@@ -509,7 +512,8 @@ describe('materializeAtGeneration — bounded & deadlock-free (GA #33)', () => {
     expect(getDeltaCalls).toBeLessThan(R * 5)
     expect(getDeltaCalls).toBeLessThan(N * N) // the regression guard
 
-    // The materialized at-gen-1 brain holds exactly the one entity that existed.
+    // The materialized brain at the first add's generation holds exactly the
+    // one user entity that existed.
     const atGen1 = await handle.find({ limit: N + 10 })
     expect(atGen1.length).toBe(1)
     await handle.close()