fix: normalize path prefix in wiki search so tenant filtering matches

get_wikijs_namespace() returns '/users/{user}' with a leading slash while
Wiki.js search results carry paths without one, so the prefix filter in
search_pages rejected every result - wiki search returned empty for every
tenant. Found by cross-repo integration verification; the librarian now
gets real search results. Compare slash-normalized on both sides.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/clients/wikijs_client.py

@@ -594,9 +594,13 @@ class WikiJSClient:
         data = await self._execute_query(gql_query, {"query": query})
         results = data.get("pages", {}).get("search", {}).get("results", [])
 
-        # Filter by path prefix if provided
+        # Filter by path prefix if provided. Wiki.js returns paths WITHOUT a
+        # leading slash while get_wikijs_namespace() produces one WITH it, so
+        # compare slash-normalized (the mismatch made this filter reject every
+        # result, returning an empty search for every tenant).
         if path_prefix:
-            results = [r for r in results if r["path"].startswith(path_prefix)]
+            prefix = path_prefix.lstrip("/")
+            results = [r for r in results if r["path"].lstrip("/").startswith(prefix)]
 
         return results