fix(frontend): resolve lazy chunk URLs against runtime base path

Vite's default chunk-preload helper prepends a hardcoded `/` to asset
filenames, so dynamic chunk preloads always 404 when the panel is
served under a non-root webBasePath (e.g. /CxuVUNgm5mRLmjPhp3/). Use
experimental.renderBuiltUrl to embed window.X_UI_BASE_PATH (injected
by dist.go) as the runtime prefix, so __vite__mapDeps emits URLs like
`<basePath>assets/<file>` regardless of where the dist is mounted.

frontend/vite.config.js

@@ -152,6 +152,16 @@ export default defineConfig({
       '@': path.resolve(__dirname, 'src'),
     },
   },
+  experimental: {
+    renderBuiltUrl(filename, { hostType }) {
+      if (hostType === 'js') {
+        return {
+          runtime: `((window.X_UI_BASE_PATH||'/')+${JSON.stringify(filename)})`,
+        };
+      }
+      return undefined;
+    },
+  },
   build: {
     outDir,
     emptyOutDir: true,