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/config.d.ts

@@ -0,0 +1,16 @@
+export { ConfigEnv, UserConfig, mergeConfig } from 'vite';
+export { ax as UserConfigExport, aw as UserConfigFn, au as UserConfigFnObject, av as UserConfigFnPromise, az as UserProjectConfigExport, ay as UserProjectConfigFn, a1 as UserWorkspaceConfig, aD as configDefaults, aG as coverageConfigDefaults, aF as defaultExclude, aE as defaultInclude, aA as defineConfig, aB as defineProject, aC as defineWorkspace, aH as extraInlineDeps } from './reporters-w_64AS5f.js';
+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';