docs(jangar): refresh control plane release gate

[gregkonush]

Summary

• Refreshes the Jangar control-plane release handoff with the current feat(jangar): surface failure-domain lease holdbacks #5454 no-go gate.
• Records the Codex-review retry, usage-limit response, green-check evidence, and zero review-thread state.
• Captures the latest Jangar Argo/Kubernetes rollout evidence, residual database warning risk, and rollback path.

Related Issues

None

Testing

• PASS: bun install --frozen-lockfile --ignore-scripts
• PASS: bunx oxfmt --check docs/agents/release-handoffs/jangar-control-plane-verify-2026-05-05.md
• PASS: git diff --check
• PASS: bun run build:docs

Screenshots (if applicable)

N/A. Documentation-only release handoff.

Breaking Changes

None.

Checklist

• Testing section documents the exact validation performed (or N/A with justification).
• Screenshots and Breaking Changes sections are handled appropriately (removed or filled in).
• Documentation, release notes, and follow-ups are updated or tracked.

[gregkonush]

Status: ready for review as of 2026-05-05T17:34Z. This PR only refreshes the Jangar release-gate handoff and records the #5454 no-go decision, Codex-review usage-limit blocker, rollout evidence, risk, and rollback path.

• Local validation passed: bun install --frozen-lockfile --ignore-scripts, bunx oxfmt --check docs/agents/release-handoffs/jangar-control-plane-verify-2026-05-05.md, git diff --check, and bun run build:docs.
• feat(jangar): surface failure-domain lease holdbacks #5454 remains unmerged and blocked by the large-diff Codex-review gate; a retry at 2026-05-05T17:21:52Z got the same connector usage-limit response.
• Jangar rollout settled Healthy after Argo synced revision e65390a0704b25c83da5ef2ea9b2a1ceafd6a9bc; current pod jangar-7575c9cdf6-26glb is 2/2 Ready on image e48d29c9.

Gate for this PR: wait for GitHub checks to finish, then merge normally if green and review-clean.