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/tailwindcss/lib/util/cloneDeep.js

@@ -0,0 +1,22 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+Object.defineProperty(exports, "cloneDeep", {
+    enumerable: true,
+    get: function() {
+        return cloneDeep;
+    }
+});
+function cloneDeep(value) {
+    if (Array.isArray(value)) {
+        return value.map((child)=>cloneDeep(child));
+    }
+    if (typeof value === "object" && value !== null) {
+        return Object.fromEntries(Object.entries(value).map(([k, v])=>[
+                k,
+                cloneDeep(v)
+            ]));
+    }
+    return value;
+}