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/environment.d.ts

@@ -0,0 +1,16 @@
+import { S as SnapshotEnvironment, a as SnapshotEnvironmentOptions } from './environment-cMiGIVXz.js';
+
+declare class NodeSnapshotEnvironment implements SnapshotEnvironment {
+    private options;
+    constructor(options?: SnapshotEnvironmentOptions);
+    getVersion(): string;
+    getHeader(): string;
+    resolveRawPath(testPath: string, rawPath: string): Promise<string>;
+    resolvePath(filepath: string): Promise<string>;
+    prepareDirectory(dirPath: string): Promise<void>;
+    saveSnapshotFile(filepath: string, snapshot: string): Promise<void>;
+    readSnapshotFile(filepath: string): Promise<string | null>;
+    removeSnapshotFile(filepath: string): Promise<void>;
+}
+
+export { NodeSnapshotEnvironment, SnapshotEnvironment };