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.

tools/README.md

@@ -104,6 +104,17 @@ reuse-surface hub sync --dry-run
 
 Run the service locally: `REUSE_SURFACE_TOKEN=dev-token reuse-surface serve`
 
+### report gaps
+
+```bash
+reuse-surface report gaps
+reuse-surface report gaps --format json
+reuse-surface report gaps --roster registry/federation/local-repo-roster.yaml
+```
+
+Workstation roster report: publish blockers, empty scaffolds, seed-ready repos,
+and local index owner stubs pending dedup.
+
 ### stats
 
 Registry maturity aggregates and federation readiness.