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/gridcellRole.js

@@ -0,0 +1,37 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = void 0;
+var gridcellRole = {
+  abstract: false,
+  accessibleNameRequired: false,
+  baseConcepts: [],
+  childrenPresentational: false,
+  nameFrom: ['author', 'contents'],
+  prohibitedProps: [],
+  props: {
+    'aria-disabled': null,
+    'aria-errormessage': null,
+    'aria-expanded': null,
+    'aria-haspopup': null,
+    'aria-invalid': null,
+    'aria-readonly': null,
+    'aria-required': null,
+    'aria-selected': null
+  },
+  relatedConcepts: [{
+    concept: {
+      constraints: ['ancestor table element has grid role', 'ancestor table element has treegrid role'],
+      name: 'td'
+    },
+    module: 'HTML'
+  }],
+  requireContextRole: ['row'],
+  requiredContextRole: ['row'],
+  requiredOwnedElements: [],
+  requiredProps: {},
+  superClass: [['roletype', 'structure', 'section', 'cell'], ['roletype', 'widget']]
+};
+var _default = exports.default = gridcellRole;