Current baseline
- stable roots with explicit boundaries: `core`, `router`, `contract`, `middleware`, `security`, `store`, `health`, `log`, `metrics`
- extension discovery and task-routing metadata under `specs/*`
- a single canonical application layout in `reference/standard-service`
- milestone, plan, card, and verify workflow assets under `tasks/*`
- repo-wide quality gates in `Makefile` and `.github/workflows/quality-gates.yml`
- stable-root compatibility policy in `docs/DEPRECATION.md`