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/aria-query/lib/etc/roles/literal/scrollbarRole.js

@@ -0,0 +1,31 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var scrollbarRole = {
+  abstract: false,
+  accessibleNameRequired: false,
+  baseConcepts: [],
+  childrenPresentational: true,
+  nameFrom: ['author'],
+  prohibitedProps: [],
+  props: {
+    'aria-disabled': null,
+    'aria-valuetext': null,
+    'aria-orientation': 'vertical',
+    'aria-valuemax': '100',
+    'aria-valuemin': '0'
+  },
+  relatedConcepts: [],
+  requireContextRole: [],
+  requiredContextRole: [],
+  requiredOwnedElements: [],
+  requiredProps: {
+    'aria-controls': null,
+    'aria-valuenow': null
+  },
+  superClass: [['roletype', 'structure', 'range'], ['roletype', 'widget']]
+};
+var _default = exports.default = scrollbarRole;