feat: expose capability and catalog documentation

README.md

@@ -55,6 +55,30 @@ Frontend package:
 
 Platform module manifests, configuration packages, release catalogs, and governance rules are documented in `govoplan-core/docs/`.
 
+Capabilities can provide generic documentation without exposing their runtime
+provider implementation:
+
+```python
+ModuleManifest(
+    capability_factories={"example.lookup": build_lookup},
+    capability_documentation={
+        "example.lookup": CapabilityDocumentation(
+            label="Example lookup",
+            summary="Resolves records through the versioned lookup contract.",
+            contract_version="2",
+            stability="stable",
+            audience=("module_admin",),
+        ),
+    },
+)
+```
+
+Docs also projects the configured module release catalog and configuration
+package catalog through the public Core catalog contracts. Catalog trust,
+freshness, provenance, descriptions, and package requirements remain visible
+as typed evidence; provider objects, credentials, and secret configuration are
+never imported into the Docs WebUI.
+
 ## Concept documents
 
 - `docs/DOCUMENTATION_LAYER_CONCEPT.md` defines the configured, available, and evidence documentation model.