fix: restore router Supabase accessor and remove client secret reference

api/state.py

@@ -69,6 +69,14 @@ def _get_sb() -> Any:
             return entry["client"]
     return _clients[0]["client"] if _clients else None
 
+def sb() -> Any:
+    """Return the current Supabase client for router compatibility.
+
+    Routers use this public accessor so pool rotation and failed-client
+    avoidance remain centralized in ``_get_sb``.
+    """
+    return _get_sb()
+
 _sb = _get_sb()
 
 @router.get("/health")