Issue complete.

Deliverables now in the repo:

- `KESTREL_FEATURES.md` rewritten as the canonical maintained inventory
- `docs/audit/FEATURE_MODULE_MATRIX.md`
- `docs/audit/FEATURE_INVENTORY_RECONCILIATION.md`
- `docs/archive/KESTREL_FEATURES_legacy.md`

Result:

- the live feature inventory is reconciled against the old catalog
- the canonical source now describes the discovered module surface instead of stale fixed plugin counts
- the legacy catalog is explicitly historical
