docs(#771): remediate database role split review

docs/scratchpads/771-kbn101-db-role-split.md

@@ -76,3 +76,15 @@ Independent Codex review found two blockers and security review found two medium
 - Pre-push queue guard: `ci-queue-wait.sh --purpose push -B main` returned `state=unknown` without failure. The push hook ran repository `pnpm typecheck`, `pnpm lint`, and `pnpm format:check`: PASS.
 - Pushed branch `docs/771-kbn101-db-role-split` at the exact commit above; no PR was opened, merged, or closed. `web1:mosaic-100` received the handoff with head, decisions, DAG, and validation.
 - Awaiting independent security/Ultron review.
+
+## 2026-07-15 — rc.6 exact-head remediation session
+
+- **Objective / correction:** Replace the prior planning-author handoff and close every finding in the [independent exact-head report](../reports/native-kanban-sot/kbn-101-contract-security-review-82ce325.md) against `da742ca2da4a2ff466916c818fe275c4f7ffd384`. The report is a verbatim durable copy of the task-supplied review artifact; scope remains documentation-only, `.mosaic` is excluded, and source/config/compose/CI/deployment/secrets/migrations remain untouched.
+- **Finding 1 — closed DDL control plane:** rc.6 names `mosaic-db-migrator` as the sole application/CI/test PostgreSQL DDL runner, requires `DATABASE_MIGRATION_URL` before connection/DDL, inventories `runMigrations`, Drizzle config/scripts, `db:push`, storage CLI, adapter/Gateway startup, fleet-backlog, extension probes/bootstrap, direct federated integration DDL, CI, and future scripts, and specifies route/deny/test disposition for each. Tests use runner-prepared disposable PostgreSQL or invoke that runner; `db:push` is local-disposable-only and rejects production-like URLs.
+- **Finding 2 — deployable TLS:** rc.6 freezes distinct runtime/migrator URL and CA/server leaf Vault/compose/Swarm secret identifiers, `0400` key and `0600` URL/cert/CA mount requirements, actual compose/Swarm service-DNS SANs, PostgreSQL TLS settings, legacy-client drain/termination plus `hostssl` enforcement, verified-TLS readiness ordering, fresh/existing transition, CA-overlap rotation/TLS-only rollback, and standalone plus federated/Swarm positive and missing/wrong CA/SAN/downgrade negatives. PGlite is explicitly non-PostgreSQL evidence.
+- **Finding 3 — manifest/0009:** rc.6 defines manifest v1 canonical UTF-8 serialization and raw SQL-byte SHA-256, logical journal order, manifest ownership/grants, exact one-to-one observed hash tuple mapping, non-normative physical insertion order, safe original-0009 conditions, ambiguous-effect fail-closed recovery, and the full required reconciliation/backup test matrix. It preserves shipped 0009 bytes and forbids manual ledger adoption/insertion.
+- **Finding 4 — advisory lock:** replaced `hashtext` with fixed signed-int4-safe `(1297044289,1262636593)` (`MOSA`,`KBN1`), one `max:1` runner session, close-on-crash semantics, and contention/crash/readiness/unrelated-key evidence.
+- **Finding 5 — identifiers/search path:** selects `mosaic`, exact `pg_catalog,mosaic` per pooled connection and `SET LOCAL` transactions, plans audited public-object/extension/Drizzle relocation, forbids config-derived identifiers, limits bootstrap quoting to server-side `%I` on fixed allowlist, and requires injection/pool-reset negatives.
+- **Finding 6 — safe DAG:** cards 00–07 are inactive prepared capability while owner-runtime remains N-1; KBN-101-08 is the one atomic activation release after platform roles/TLS and compatible code. Mosaic control plane/Jason alone can activate/rollback; no force-on-red, runtime bypass, or temporary compatibility survives the gate. The approved role graph, post-KBN-100 immutable certification, and KBN-105 gate remain unchanged.
+- **Review remediation:** Codex review found the legacy plaintext cutover gap, missing URL-secret bindings, historical `public` migration incompatibility, non-reproducible checkout-byte hashing, CONNECT allowlisting regression, and undocumented direct-DDL operator instructions. rc.6 now requires drain/scale-to-zero, residual non-TLS session termination, `hostssl` with no `host` rule, zero plaintext-session proof, TLS-only post-enforcement rollback, distinct named runtime/migrator secret consumers, canonical Git-blob/LF manifest bytes, a runner-only owner-controlled legacy-public bootstrap followed by `mosaic` relocation, explicit CONNECT/TEMP revocation, and KBN-101-07 replacement of direct-DDL documentation. It also required the durable exact-head report link above. Pre-existing `.mosaic` runtime state remains excluded.
+- **Validation:** Prettier on all changed Markdown, repository Markdown link/whitespace check, and strict native-kanban contract TypeScript passed before final staging; the final staged diff excludes `.mosaic`. No source-code TDD applies because this is contract-only remediation.