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/@tanstack/react-query/build/query-codemods/vite.config.ts

@@ -0,0 +1,30 @@
+import { defineConfig } from 'vitest/config'
+
+import packageJson from './package.json'
+
+export default defineConfig({
+  // fix from https://github.com/vitest-dev/vitest/issues/6992#issuecomment-2509408660
+  resolve: {
+    conditions: ['@tanstack/custom-condition'],
+  },
+  environments: {
+    ssr: {
+      resolve: {
+        conditions: ['@tanstack/custom-condition'],
+      },
+    },
+  },
+  test: {
+    name: packageJson.name,
+    dir: './src',
+    watch: false,
+    globals: true,
+    coverage: {
+      enabled: true,
+      provider: 'istanbul',
+      include: ['src/**/*.{js,ts,cjs,mjs,jsx,tsx}'],
+    },
+    typecheck: { enabled: true },
+    restoreMocks: true,
+  },
+})