REUSE-WP-0015: dedup owner entries, add report gaps (T02/T03/T05)

Remove 17 owner-migrated capabilities from reuse-surface index (keep
activity-core stub). Add report gaps CLI, roster stats + gaps CI steps.
T01 remains operator-blocked on Gitea publish.

.gitea/workflows/ci.yml

@@ -35,8 +35,16 @@ jobs:
       - name: Registry stats (informational)
         run: reuse-surface stats || true
 
+      - name: Workstation roster federation stats (informational)
+        run: |
+          reuse-surface stats --roster registry/federation/local-repo-roster.yaml \
+            --federation-ready --format json || true
+
       - name: Planning cohort report (informational)
         run: reuse-surface report cohorts --planning-min D4 || true
 
+      - name: Registry gap report (informational)
+        run: reuse-surface report gaps || true
+
       - name: Run tests
         run: pytest -q