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/react-smooth/lib/setRafTimeout.js

@@ -0,0 +1,25 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = setRafTimeout;
+function safeRequestAnimationFrame(callback) {
+  if (typeof requestAnimationFrame !== 'undefined') requestAnimationFrame(callback);
+}
+function setRafTimeout(callback) {
+  var timeout = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
+  var currTime = -1;
+  var shouldUpdate = function shouldUpdate(now) {
+    if (currTime < 0) {
+      currTime = now;
+    }
+    if (now - currTime > timeout) {
+      callback(now);
+      currTime = -1;
+    } else {
+      safeRequestAnimationFrame(shouldUpdate);
+    }
+  };
+  requestAnimationFrame(shouldUpdate);
+}