fix: honor explicit human delivery acceptance

[fujiwaranosai850]

Summary

• add explicit candidate decision comments so human-routed acceptance has an observable gate
• keep human-routed promotion gated on explicit candidate records
• wire delivery-transition heartbeat totals into the aggregated heartbeat logger

Testing

• npx tsx --test lib/services/delivery-phases.test.ts lib/services/pipeline-delivery.test.ts lib/config/schema.test.ts

Notes

• npm run check still reports pre-existing workspace issues unrelated to this change (missing vitest/openclaw type deps and existing work-finish test/type errors).