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/dom-helpers/cjs/matches.js

@@ -0,0 +1,26 @@
+"use strict";
+
+exports.__esModule = true;
+exports.default = matches;
+var matchesImpl;
+/**
+ * Checks if a given element matches a selector.
+ * 
+ * @param node the element
+ * @param selector the selector
+ */
+
+function matches(node, selector) {
+  if (!matchesImpl) {
+    var body = document.body;
+    var nativeMatch = body.matches || body.matchesSelector || body.webkitMatchesSelector || body.mozMatchesSelector || body.msMatchesSelector;
+
+    matchesImpl = function matchesImpl(n, s) {
+      return nativeMatch.call(n, s);
+    };
+  }
+
+  return matchesImpl(node, selector);
+}
+
+module.exports = exports["default"];