docs(scanner): Beam batch 7 — all 10 scanner endpoints backfilled

Scanner surface frontmatter'd (scan/start/stop/cancel/status/active/
active-summary + watch start/stop/status) with provenance comments;
active-summary on a non-admin group.

Claude registry: 10 entries. Fixed handler drift Beam missed: scan_library
request has no "recursive"; scanner/start binds folder_paths (not
invented interval_seconds); scanner/stop binds no body; response is
{message, job_id, status} with 409 coalescing variant
{error, active_job_id}.

Gate fix in drift_test seed: registerScannerRoutes group seeds used bare
"jwt"/"admin" tokens invisible to authLabel; and silently passed before
only because the seeded set was unchecked. Seeds now 'jwtMiddleware'/
'AdminMiddleware' markers. Also: cleanup of a stale-merge-script residue
in collections/update_rule.md example (extra null keys). make test 9/9.

docs/developer/api/collections/update_rule.md

@@ -26,13 +26,7 @@ the rules endpoint.
 ```json example-response
 {
   "collection_id": "550e8400-e29b-41d4-a716-446655440000",
-  "is_smart": true,
-  "enabled": null,
-  "field": null,
-  "id": null,
-  "operator": null,
-  "priority": null,
-  "value": null
+  "is_smart": true
 }
 ```