feat(health): the gate reads the named report — reads refuse loudly, never rebuild; open serves before it returns; the ceremony door

The read gate stops consulting the unnamed isReady() boolean: every provider
may expose healthReport() (sync, O(1), composed from exact ledgers —
HealthReport with a monotonic generation, per-invariant source
ledger|deep|unledgered, missing {count, sample}), and one readiness
authority (assessProviderHealth) derives the verdict. Unledgered families
are UNKNOWN — never healthy, never broken; a report that throws is a loud
not-ready, never a shrug. Reads at the four index choke points refuse with
the typed NotReady errors, narrated once per (provider, generation) — a
read NEVER starts a store walk:

- the first-read lazy build retires (open builds instead, regardless of
  size — the ≥10k deferral and the "lazy loading on first query" branch go;
  disableAutoRebuild is re-meant honestly in its docs);
- the verify*Live read-path rebuild triggers retire (refuse-or-serve);
- the read-time consistency probe that could launch a dark rebuild from an
  ordinary find() retires;
- repairIndex({ rebuild: ['metadata'|'graph'|'vector'] | 'all' }) is the
  one explicit door: rebuilds the named leg unconditionally and reports
  rebuilt per family; bare repairIndex() stays report-driven.

test(lifecycle): the biography lane — a store's whole life, refereed

tests/lifecycle/: an independent shadow model referees every read after
every chapter (founding, a working day, clean restart, crash, repair,
second life). Chapters 1-3 green. Chapters 4-6 assert the true contract and
are marked .fails as a release-blocking finding (the kill-matrix
convention): after a crash + adopt reopen the metadata index computes its
'catchup' watermark verdict and nothing consumes it — find() serves the
pre-crash index while canonical and counts recover. The catchup wiring is
the cure; a passing .fails will force the marker's removal. The lane runs
in the integration gate (config + coverage guard).

tests/unit/test-suite-coverage-guard.test.ts

@@ -63,6 +63,9 @@ function inGate(rel: string): boolean {
   return (
     rel.startsWith('tests/unit/') ||
     rel.startsWith('tests/integration/') ||
+    // The lifecycle biography lane — included by the integration config
+    // ('tests/lifecycle/**/*.test.ts'; see tests/lifecycle/README.md).
+    rel.startsWith('tests/lifecycle/') ||
     rel.endsWith('.unit.test.ts') ||
     rel.endsWith('.integration.test.ts')
   )