feat(registry): complete ATLAS-WP-0002 T05 — federate config-atlas; WP-0002 finished

Register config-atlas in reuse-surface federation and reserve the surface.*
namespace (reuse-surface commit 08f3bb5). Mark T05 done and WP-0002 finished
(6/6 tasks complete).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

workplans/ATLAS-WP-0002-registry-foundation.md

@@ -4,7 +4,7 @@ type: workplan
 title: "Configuration atlas registry foundation"
 domain: infotech
 repo: config-atlas
-status: ready
+status: finished
 owner: codex
 topic_slug: custodian
 created: "2026-06-26"
@@ -149,11 +149,20 @@ This is the start of the Phase 1 seed (target 10–20).
 
 ```task
 id: ATLAS-WP-0002-T05
-status: todo
+status: done
 priority: medium
 state_hub_task_id: "2a27434b-4eed-419a-b903-07cff9027bd6"
 ```
 
+Result 2026-06-26: Registered config-atlas in reuse-surface
+(`registry/federation/sources.yaml` + `local-repo-roster.yaml`) and reserved the
+`surface.*` namespace via a new "Id namespace ownership" section in
+`docs/RegistryFederation.md` (surface.* is a typed sibling of capability.*, not
+federated). `federation compose` succeeds (config-atlas capability now in
+`federated.yaml`). Committed in reuse-surface as 08f3bb5. Raw URL returns 303
+(required:false) — fetchability awaits the same publish fix tracked for
+state-hub/feature-control; not a config-atlas-side blocker.
+
 Reserve the `surface.*` id namespace in the reuse-surface federation roster so the
 configuration-surface registry interoperates with the capability surface without
 collision (PRD FR-10; ecosystem-boundaries §2.6). Treat the surface entry as a