fix(test): avoid Vite runtime import in UI config helpers

ui/vite.config.ts

@@ -3,7 +3,7 @@ import fs from "node:fs";
 import { createRequire } from "node:module";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
-import { defineConfig, type Plugin } from "vite";
+import type { Plugin, UserConfig } from "vite";
 import { controlUiManualChunk } from "./config/control-ui-chunking.ts";
 
 const here = path.dirname(fileURLToPath(import.meta.url));
@@ -220,7 +220,7 @@ function controlUiServiceWorkerBuildIdPlugin(buildId: string): Plugin {
   };
 }
 
-export default defineConfig(() => {
+export default function controlUiViteConfig(): UserConfig {
   const envBase = process.env.OPENCLAW_CONTROL_UI_BASE_PATH?.trim();
   const base = envBase ? normalizeBase(envBase) : "./";
   const controlUiBuildId = resolveControlUiBuildId();
@@ -282,4 +282,4 @@ export default defineConfig(() => {
       },
     ],
   };
-});
+}