fix: default benchmark form values

src/atoms/benchmark.ts

@@ -0,0 +1,15 @@
+import { atom } from 'jotai';
+
+export const benchmarkTargetInstanceAtom = atom<{
+  cluster_id: number | null;
+  model_name: string;
+  model_id: number | null;
+  model_instance_name: string;
+  model_instance: string[];
+}>({
+  cluster_id: null,
+  model_name: '',
+  model_id: null,
+  model_instance_name: '',
+  model_instance: []
+});