Harness 4.4 Certify Codex on darwin-x64 and linux-arm64 [inspector] #6553

Part of #6535.

1. The conformance legs exist with certified: false (scripts/plan-local-harness-conformance.mjs ~30-31). Flip them once evidence exists.
2. Add the targets to nativeTargets (local/compatibility.ts ~343).
3. Pass scripts/check-local-harness-release.mjs --require-ready.
4. Follow the promotion steps in ~/.claude/skills/local-harness-e2e/SKILL.md (~220-234).

Delivery rules

• Fresh worktree and branch; each PR at most 400 handwritten changed lines; stack when necessary.
• Verify the actual failing boundary and run repository checks.
• Preserve broker-only model auth, no venue/engine fallback, and separate infrastructure failures.
• Human-only: production deployment, flags/env changes, rebuilds/backfills, signed/published packs and large paid runs.

Status: planned; completion requires the acceptance evidence above.