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/pretty-format/build/collections.d.ts

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+import type { Config, Printer, Refs } from './types';
+/**
+ * Return entries (for example, of a map)
+ * with spacing, indentation, and comma
+ * without surrounding punctuation (for example, braces)
+ */
+export declare function printIteratorEntries(iterator: Iterator<[unknown, unknown]>, config: Config, indentation: string, depth: number, refs: Refs, printer: Printer, separator?: string): string;
+/**
+ * Return values (for example, of a set)
+ * with spacing, indentation, and comma
+ * without surrounding punctuation (braces or brackets)
+ */
+export declare function printIteratorValues(iterator: Iterator<unknown>, config: Config, indentation: string, depth: number, refs: Refs, printer: Printer): string;
+/**
+ * Return items (for example, of an array)
+ * with spacing, indentation, and comma
+ * without surrounding punctuation (for example, brackets)
+ **/
+export declare function printListItems(list: ArrayLike<unknown>, config: Config, indentation: string, depth: number, refs: Refs, printer: Printer): string;
+/**
+ * Return properties of an object
+ * with spacing, indentation, and comma
+ * without surrounding punctuation (for example, braces)
+ */
+export declare function printObjectProperties(val: Record<string, unknown>, config: Config, indentation: string, depth: number, refs: Refs, printer: Printer): string;