Resolves #13750

Fixes the Golden Path freeze at the scheduler / lease root instead of adding a filesystem fallback. The shared heavy-maintenance lease now supports explicit compatible-owner execution, so githubWorkflowSync can run while local kbSync owns the lease and refresh issue graph state instead of self-deferring. Golden Path now treats githubWorkflowSync as a graph-producing dependency, so synthesis waits for the sync/ingest path rather than reading stale graph state mid-refresh.

Evidence: L2 focused unit coverage -> L4 post-merge daemon validation required for live cadence. Residual: #13624 still owns the broader net-progress / idle-condition accounting beyond this starvation mechanism.

Deltas from ticket

• Delivers the heavy-maintenance lease starvation path named in the #13750 bisect.
• Keeps Golden Path graph-authoritative: no synced-markdown fallback, no handoff rendering workaround.
• Extends the existing memory-summary-backfill / kbSync compatibility through the child CLI layer too, because the same self-deferral bug class existed there.

Test Evidence

• node --check ai/daemons/orchestrator/services/HeavyMaintenanceLeaseService.mjs
• node --check ai/daemons/orchestrator/services/MaintenanceBackpressureService.mjs
• node --check ai/scripts/maintenance/syncGithubWorkflow.mjs
• node --check ai/scripts/lifecycle/backfill-memory-summaries.mjs
• npm run test-unit -- test/playwright/unit/ai/daemons/orchestrator/services/HeavyMaintenanceLeaseService.spec.mjs test/playwright/unit/ai/daemons/orchestrator/services/MaintenanceBackpressureService.spec.mjs test/playwright/unit/ai/daemons/orchestrator/scheduling/registry.spec.mjs test/playwright/unit/ai/daemons/orchestrator/scheduling/picker.spec.mjs test/playwright/unit/ai/daemons/orchestrator/scheduling/pipeline.spec.mjs test/playwright/unit/ai/scripts/maintenance/syncGithubWorkflow.spec.mjs test/playwright/unit/ai/daemons/orchestrator/daemon.spec.mjs — 111 passed after rebase onto origin/dev
• git diff --check

Post-Merge Validation

• Restart the live orchestrator and verify githubWorkflowSync runs when kbSync is active or holds the heavy-maintenance lease.
• Verify issue-to-graph ingestion catches current #137xx issues and Golden Path no longer recommends stale non-board work.
• Verify the next resources/content/sandman_handoff.md refresh is produced by the graph path, not a fallback.

Commits

• 6f564fdd9c — fix(ai): prevent Golden Path sync starvation (#13750)

Authored by Euclid (GPT-5, Codex Desktop). Session 019ee5c2-82ba-7b73-8812-df59106ff61a.