Implement REUSE-WP-0013 registry establish, update, and stats

Add stats, establish (scaffold, publish-check, discover), and update CLI
commands with optional llm-connect bridge, validate --root for sibling repos,
pytest coverage, and documentation for sibling registry onboarding.

SCOPE.md

@@ -60,6 +60,11 @@ The MVP registry foundation, CLI tooling (REUSE-WP-0003), federation stack
   against `https://reuse.coulomb.social`
 - **Sync local federation manifest from hub** with `reuse-surface hub sync`
 - **Export planning cohorts** with `reuse-surface report cohorts`
+- **Bootstrap a sibling registry** with `reuse-surface establish --scaffold`
+- **Verify index publish readiness** with `reuse-surface establish --publish-check`
+- **View registry stats** with `reuse-surface stats`
+- **Draft or refresh entries** with `reuse-surface establish --discover` and
+  `reuse-surface update` (optional llm-connect backend)
 - **Run the hub locally or in a container** with `reuse-surface serve`
 - **Generate relation graphs** with `reuse-surface graph`
 - **Explore relations interactively** at `docs/graph/index.html`
@@ -104,8 +109,8 @@ See `tools/README.md` for command reference.
 - **Federated index:** `registry/indexes/federated.yaml` (local compose).
 - **Relation graph:** `docs/graph/capability-graph.mmd`, `docs/graph/index.html`.
 - **Searchable catalog:** `docs/catalog/search.html`.
-- **Workplans:** REUSE-WP-0001 through REUSE-WP-0011 finished; WP-0011 archived;
-  **REUSE-WP-0012** finished (federation scale + intent alignment).
+- **Workplans:** REUSE-WP-0001 through REUSE-WP-0012 finished/archived;
+  **REUSE-WP-0013** finished (registry establish/update/stats).
 - **Assessment history:** `history/2026-06-15-intent-scope-assessment.md`.
 - **Self-assessed vector:** `D5 / A4 / C5 / R3` (see `docs/IntentScopeGapAnalysis.md`).