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/@babel/runtime/helpers/regeneratorValues.js

@@ -0,0 +1,19 @@
+var _typeof = require("./typeof.js")["default"];
+function _regeneratorValues(e) {
+  if (null != e) {
+    var t = e["function" == typeof Symbol && Symbol.iterator || "@@iterator"],
+      r = 0;
+    if (t) return t.call(e);
+    if ("function" == typeof e.next) return e;
+    if (!isNaN(e.length)) return {
+      next: function next() {
+        return e && r >= e.length && (e = void 0), {
+          value: e && e[r++],
+          done: !e
+        };
+      }
+    };
+  }
+  throw new TypeError(_typeof(e) + " is not iterable");
+}
+module.exports = _regeneratorValues, module.exports.__esModule = true, module.exports["default"] = module.exports;