Close REUSE-WP-0011 follow-ups: archive, docs, A4 promotion

- Archive workplan to workplans/archived/260615-REUSE-WP-0011-*.md
- Document browser landing page routing in FederationHubAPI and deploy docs
- Promote capability.registry.register to A4 (hosted hub API evidence)
- Update SCOPE finished workplan list

registry/capabilities/capability.registry.register.md

@@ -20,12 +20,14 @@ maturity:
       registry model is bounded in INTENT.md, but concrete promotion workflows
       are not yet grounded in registry artifacts.
   availability:
-    current: A3
-    target: A3
+    current: A4
+    target: A5
     confidence: medium
     rationale: >
-      Registration and maintenance are automatable through the reuse-surface CLI
-      for validate, query, and export workflows.
+      Local registry workflows use the reuse-surface CLI (A3). Federation repo
+      registration is also available through the hosted hub HTTP API at
+      reuse.coulomb.social (POST/PATCH /v1/repos), deployed and dogfood-tested
+      on Railiance01 (REUSE-WP-0011).
 
 external_evidence:
   completeness:
@@ -38,6 +40,7 @@ external_evidence:
       - maturity vectors can be recorded at registration time
       - CLI validate, query, and export support registry workflows
       - promotion history can be recorded in entries
+      - federation repo registration via hosted hub API and hub CLI
     broken_expectations:
       - no automated duplicate detection yet
     out_of_scope_expectations:
@@ -76,17 +79,22 @@ discovery:
     - specs/ProductRequirementsDocument.md
 
 availability:
-  current_level: A3
-  target_level: A3
+  current_level: A4
+  target_level: A5
   current_artifacts:
     - templates/capability-entry.template.md
     - registry/indexes/capabilities.yaml
     - reuse_surface/cli.py
-  target_artifacts: []
+    - reuse_surface/hub/
+    - specs/FederationHubAPI.md
+    - https://reuse.coulomb.social
+  target_artifacts:
+    - packaged container release with documented SLO
   consumption_modes:
     - informational
     - markdown authoring
     - cli
+    - service API
 
 relations:
   depends_on: []
@@ -100,7 +108,10 @@ evidence:
   documentation:
     - INTENT.md
     - specs/UseCaseCatalog.md
-  tests: []
+    - specs/FederationHubAPI.md
+    - docs/deploy/reuse-kubernetes.md
+  tests:
+    - tests/test_hub.py
   consumer_feedback: []
   bug_reports: []
   incidents: []
@@ -135,6 +146,14 @@ promotion_history:
     to: A3
     rationale: reuse-surface CLI shipped validate, query, and export commands.
     author: reuse-surface
+  - date: "2026-06-15"
+    dimension: availability
+    from: A3
+    to: A4
+    rationale: >
+      Hosted federation hub live at reuse.coulomb.social; hub register/update
+      via HTTP API and reuse-surface hub CLI; production deploy on Railiance01.
+    author: reuse-surface
 ---
 
 # Capability Registration
@@ -147,12 +166,15 @@ documentation exists elsewhere.
 
 ## Current reuse mode
 
-Humans and agents add Markdown entries under `registry/capabilities/` and update
-`registry/indexes/capabilities.yaml`. This is informational reuse (A0): read,
-plan, and author entries.
+**Local registry (A3 CLI):** add Markdown entries under `registry/capabilities/`,
+update `registry/indexes/capabilities.yaml`, run `reuse-surface validate`.
+
+**Federation registration (A4 API):** register published index URLs on the hosted
+hub (`reuse-surface hub register`, `POST /v1/repos`) for cross-repo discovery
+via `GET /v1/federated`.
 
 ## Next promotion steps
 
 1. Attach concrete use cases and actors to reach D5.
-2. Add a CLI validator to reach A3.
+2. Package hub as a versioned container release with operator SLO (A5).
 3. Record consumer expectations and broken expectations as external evidence.