Add Admin control for fundamentals cutover

frontend/src/hooks/useAdmin.ts

@@ -90,6 +90,36 @@ export function useUpdateSetting() {
   });
 }
 
+export function useFundamentalsCutoverSettings() {
+  return useQuery({
+    queryKey: ['admin', 'fundamentals-cutover'],
+    queryFn: () => adminApi.getFundamentalsCutoverSettings(),
+  });
+}
+
+export function useUpdateFundamentalsCutoverSettings() {
+  const qc = useQueryClient();
+  const { addToast } = useToast();
+
+  return useMutation({
+    mutationFn: (enabled: boolean) =>
+      adminApi.updateFundamentalsCutoverSettings(enabled),
+    onSuccess: (config) => {
+      qc.setQueryData(['admin', 'fundamentals-cutover'], config);
+      qc.invalidateQueries({ queryKey: ['admin', 'settings'] });
+      addToast(
+        config.enabled ? 'success' : 'info',
+        config.enabled
+          ? 'SEC + Dolt fundamentals activated'
+          : 'SEC + Dolt cache refresh paused',
+      );
+    },
+    onError: (error: Error) => {
+      addToast('error', error.message || 'Failed to update fundamentals data source');
+    },
+  });
+}
+
 export function useRecommendationSettings() {
   return useQuery({
     queryKey: ['admin', 'recommendation-settings'],