feat(registry): complete ATLAS-WP-0002 T02, T03, T06

T02: remove inherited capability.infotech.repo-template and template consumer
docs (statehub-register, template-validation-checklist); add
capability.infotech.config-surface-atlas and rewrite capabilities.yaml.

T03: seed 4 configuration surfaces (state-hub api-config, ops-warden
routing-catalog, reuse-surface federation-sources, ops-bridge tunnel-config)
with registry/indexes/surfaces.yaml; source-linked, no values, secret deps by
reference.

T06: add tools/validate_registry.py (schema + index gate), Makefile (make
validate), and .github/workflows/validate.yml (GitHub + Gitea Actions);
document in stack-and-commands. Verified malformed entries are rejected.

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

registry/surfaces/surface.infotech.reuse-surface.federation-sources.md

@@ -0,0 +1,44 @@
+---
+id: surface.infotech.reuse-surface.federation-sources
+name: reuse-surface federation sources
+kind: app-config
+summary: Federation roster and source list that define which registries reuse-surface aggregates, including the reserved id namespaces.
+owner: reuse-surface
+status: active
+scope:
+  allowed_layers: [company, platform, installation]
+  default_layer: company
+mutability: hot-reloadable
+security_class: operational
+schema:
+  type: object
+  validator: ~/reuse-surface/schemas/federation.schema.yaml
+sources:
+  - repo: reuse-surface
+    path: registry/federation/sources.yaml
+    role: company-baseline
+  - repo: reuse-surface
+    path: registry/federation/local-repo-roster.yaml
+    role: installation-overlay
+relations:
+  consumed_by:
+    - service.reuse-surface-hub
+  overrides: []
+  depends_on_secret: []
+  related_to:
+    - surface.infotech.state-hub.api-config
+evidence:
+  last_seen: '2026-06-26'
+  discovery_method: manual
+  change_log_ref: ATLAS-WP-0002-T03
+---
+
+# reuse-surface federation sources
+
+The federation sources configure which registries reuse-surface aggregates and the
+id namespaces each owns. config-atlas federates here as a typed peer (the `surface.*`
+namespace reservation is ATLAS-WP-0002-T05).
+
+- **Source of truth:** `reuse-surface/registry/federation/{sources,local-repo-roster}.yaml`.
+- **Why indexed:** this is the surface that governs cross-registry interoperability;
+  config-atlas's own discoverability depends on it.