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/snapshot/dist/manager.d.ts

@@ -0,0 +1,18 @@
+import { S as SnapshotStateOptions, f as SnapshotSummary, b as SnapshotResult } from './index-S94ASl6q.js';
+import 'pretty-format';
+import './environment-cMiGIVXz.js';
+
+declare class SnapshotManager {
+    options: Omit<SnapshotStateOptions, 'snapshotEnvironment'>;
+    summary: SnapshotSummary;
+    extension: string;
+    constructor(options: Omit<SnapshotStateOptions, 'snapshotEnvironment'>);
+    clear(): void;
+    add(result: SnapshotResult): void;
+    resolvePath(testPath: string): string;
+    resolveRawPath(testPath: string, rawPath: string): string;
+}
+declare function emptySummary(options: Omit<SnapshotStateOptions, 'snapshotEnvironment'>): SnapshotSummary;
+declare function addSnapshotResult(summary: SnapshotSummary, result: SnapshotResult): void;
+
+export { SnapshotManager, addSnapshotResult, emptySummary };