docs: record Alesha's APPROVED GO to prod durable-SHADOW (sign-off complete; shadow runbook refreshed; no prod action)
docs(durable-eventlog): slice 6 prod-durability sign-off package (ehdb#254) New Runbook-Durable-EventLog-Prod-Signoff page — go/no-go checklist (D1-D11), evidence bundle (slices 1-5), residual-risk register (R1-R7), and the extended durable-shadow -> durable-primary prod rollout sequence. Cross-linked from the tier-1 cutover runbook (§C update + Related), the design page, and _Sidebar; Sessions-Log + Home updated. Docs/planning only — no prod action; ehdb#254 slice-6 box stays unchecked.
docs(runbook): Phase 9 tier-1 event-log PROD cutover runbook (draft — awaiting user go) Staged A→B→C plan (deploy v5.66.0 flags-off → shadow → primary), prod deploy mechanism grounded in the ops CQRS-flip runbook (GKE ctx, kubectl set env, GMP monitoring), tier-1 rollback levers, and the local_reference pod-local-JSONL durability blocker for Stage C. Nothing executed. Linked from Roadmap Phase 9 tier-1 row + tier-1 section + _Sidebar Runbooks. Refs noetl/ehdb#241