fix: bound sidebar session-list cache

api/routes.py

@@ -2295,8 +2295,11 @@ def _build_session_list_cache_payload(
         )
 
     def _all_sessions_for_sidebar():
+        kwargs = {"diag": diag, "include_lineage_metadata": False}
+        if _callable_accepts_kwarg(all_sessions, "sidebar_metadata_only"):
+            kwargs["sidebar_metadata_only"] = True
         if _callable_accepts_kwarg(all_sessions, "include_lineage_metadata"):
-            return all_sessions(diag=diag, include_lineage_metadata=False)
+            return all_sessions(**kwargs)
         # Focused tests and third-party callers sometimes monkeypatch
         # routes.all_sessions with the historical diag-only signature.
         return all_sessions(diag=diag)