security(docs): hide runtime provider failures from users

src/govoplan_docs/backend/api/v1/routes.py

@@ -113,7 +113,7 @@ def docs_context(
             },
             "evidence": {
                 "optional_modules": optional_modules,
-                "sources": _evidence_sources(),
+                "sources": _evidence_sources() if documentation_type == "admin" else [],
                 "documentation": documentation_layers["evidence"],
             },
         },
@@ -356,6 +356,8 @@ def _collect_documentation_topics(
             try:
                 provided_topics = tuple(provider(context))
             except Exception as exc:
+                if documentation_type != "admin":
+                    continue
                 provided_topics = (
                     DocumentationTopic(
                         id=f"{manifest.id}.runtime-documentation-unavailable",