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/axios/lib/helpers/fromDataURI.js

@@ -0,0 +1,53 @@
+'use strict';
+
+import AxiosError from '../core/AxiosError.js';
+import parseProtocol from './parseProtocol.js';
+import platform from '../platform/index.js';
+
+const DATA_URL_PATTERN = /^(?:([^;]+);)?(?:[^;]+;)?(base64|),([\s\S]*)$/;
+
+/**
+ * Parse data uri to a Buffer or Blob
+ *
+ * @param {String} uri
+ * @param {?Boolean} asBlob
+ * @param {?Object} options
+ * @param {?Function} options.Blob
+ *
+ * @returns {Buffer|Blob}
+ */
+export default function fromDataURI(uri, asBlob, options) {
+  const _Blob = (options && options.Blob) || platform.classes.Blob;
+  const protocol = parseProtocol(uri);
+
+  if (asBlob === undefined && _Blob) {
+    asBlob = true;
+  }
+
+  if (protocol === 'data') {
+    uri = protocol.length ? uri.slice(protocol.length + 1) : uri;
+
+    const match = DATA_URL_PATTERN.exec(uri);
+
+    if (!match) {
+      throw new AxiosError('Invalid URL', AxiosError.ERR_INVALID_URL);
+    }
+
+    const mime = match[1];
+    const isBase64 = match[2];
+    const body = match[3];
+    const buffer = Buffer.from(decodeURIComponent(body), isBase64 ? 'base64' : 'utf8');
+
+    if (asBlob) {
+      if (!_Blob) {
+        throw new AxiosError('Blob is not supported', AxiosError.ERR_NOT_SUPPORT);
+      }
+
+      return new _Blob([buffer], { type: mime });
+    }
+
+    return buffer;
+  }
+
+  throw new AxiosError('Unsupported protocol ' + protocol, AxiosError.ERR_NOT_SUPPORT);
+}