feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/node_modules/vitest/dist/environments.d.ts

@@ -0,0 +1,35 @@
+import { E as Environment } from './reporters-w_64AS5f.js';
+import 'vite';
+import '@vitest/runner';
+import 'vite-node';
+import '@vitest/snapshot';
+import '@vitest/expect';
+import '@vitest/runner/utils';
+import '@vitest/utils';
+import 'tinybench';
+import 'node:stream';
+import 'vite-node/client';
+import '@vitest/snapshot/manager';
+import 'vite-node/server';
+import 'node:worker_threads';
+import 'node:fs';
+import 'chai';
+
+declare const environments: {
+    node: Environment;
+    jsdom: Environment;
+    'happy-dom': Environment;
+    'edge-runtime': Environment;
+};
+
+interface PopulateOptions {
+    bindFunctions?: boolean;
+    additionalKeys?: string[];
+}
+declare function populateGlobal(global: any, win: any, options?: PopulateOptions): {
+    keys: Set<string>;
+    skipKeys: string[];
+    originals: Map<string | symbol, any>;
+};
+
+export { environments as builtinEnvironments, populateGlobal };