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/@testing-library/dom/dist/queries/alt-text.js

@@ -0,0 +1,24 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.queryByAltText = exports.queryAllByAltText = exports.getByAltText = exports.getAllByAltText = exports.findByAltText = exports.findAllByAltText = void 0;
+var _queryHelpers = require("../query-helpers");
+var _helpers = require("../helpers");
+var _allUtils = require("./all-utils");
+// Valid tags are img, input, area and custom elements
+const VALID_TAG_REGEXP = /^(img|input|area|.+-.+)$/i;
+const queryAllByAltText = (container, alt, options = {}) => {
+  (0, _helpers.checkContainerType)(container);
+  return (0, _queryHelpers.queryAllByAttribute)('alt', container, alt, options).filter(node => VALID_TAG_REGEXP.test(node.tagName));
+};
+const getMultipleError = (c, alt) => `Found multiple elements with the alt text: ${alt}`;
+const getMissingError = (c, alt) => `Unable to find an element with the alt text: ${alt}`;
+const queryAllByAltTextWithSuggestions = exports.queryAllByAltText = (0, _queryHelpers.wrapAllByQueryWithSuggestion)(queryAllByAltText, queryAllByAltText.name, 'queryAll');
+const [queryByAltText, getAllByAltText, getByAltText, findAllByAltText, findByAltText] = (0, _allUtils.buildQueries)(queryAllByAltText, getMultipleError, getMissingError);
+exports.findByAltText = findByAltText;
+exports.findAllByAltText = findAllByAltText;
+exports.getByAltText = getByAltText;
+exports.getAllByAltText = getAllByAltText;
+exports.queryByAltText = queryByAltText;