chore: restore checker CI gate

.scratch/saas-production-readiness/map.md

@@ -26,9 +26,9 @@ rollback and recovery, and no known critical security or data-integrity gaps.
   unrelated Organizations is not an acceptable destination state.
 - Use the `diagnosing-bugs` loop for every reproduced defect. Prefer explicit
   failures and observable critical paths over fallback behavior.
-- Work on `saas-production-readiness`; make small conventional commits after
-  verified, independently reversible milestones. Do not push without explicit
-  authorization.
+- Work directly on `main` per developer authorization; make small conventional
+  commits after verified, independently reversible milestones. Do not push
+  without explicit authorization.
 - Local `lake build` currently requires a configured elan toolchain; CI remains
   the authoritative configured Lean build environment until that local toolchain
   is available.
@@ -43,6 +43,7 @@ rollback and recovery, and no known critical security or data-integrity gaps.
 - [Audit backup, migration, and disaster recovery safety](issues/06-audit-backup-migration-recovery.md) — separate persistent state from releases, define a database/workspace checkpoint and recovery objectives, make migrations compatibility-gated, and prove complete off-host backup sets through isolated restore and cutover drills.
 - [Audit the accepted product surface for production completeness](issues/07-audit-product-surface-completeness.md) — retain the guarded Organization APIs and single-app Feishu vertical slice, but require explicit Organization-scoped Feishu/provider connections and external-identity namespaces, private platform and Organization admin control planes, and the full ADR-0022 capacity surface before release.
 - [Decide the platform-administrator identity and audit boundary](issues/42-decide-platform-admin-identity-audit.md) — use a dedicated platform Feishu issuer, one peer administrator role, guarded bootstrap and identity-bound invitations, revocable server-side sessions, atomic append-only Platform Audit, and dual-factor offline recovery without a standing break-glass account.
+- [Restore the checker formatting gate](issues/09-restore-checker-format-gate.md) — pin local and CI Rust/rustfmt/clippy to 1.92.0, apply the canonical workspace format, and keep the full fmt + clippy + 53-test checker gate green.
 
 ## Fog