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/object-keys/.eslintrc

@@ -0,0 +1,17 @@
+{
+	"root": true,
+
+	"extends": "@ljharb",
+
+	"rules": {
+		"complexity": [2, 23],
+		"id-length": [2, { "min": 1, "max": 40 }],
+		"max-params": [2, 3],
+		"max-statements": [2, 23],
+		"max-statements-per-line": [2, { "max": 2 }],
+		"no-extra-parens": [1],
+		"no-invalid-this": [1],
+		"no-restricted-syntax": [2, "BreakStatement", "ContinueStatement", "LabeledStatement", "WithStatement"],
+		"operator-linebreak": [2, "after"]
+	}
+}