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/array-buffer-byte-length/index.js

@@ -0,0 +1,14 @@
+'use strict';
+
+var callBound = require('call-bound');
+var $byteLength = callBound('ArrayBuffer.prototype.byteLength', true);
+
+var isArrayBuffer = require('is-array-buffer');
+
+/** @type {import('.')} */
+module.exports = function byteLength(ab) {
+	if (!isArrayBuffer(ab)) {
+		return NaN;
+	}
+	return $byteLength ? $byteLength(ab) : ab.byteLength;
+}; // in node < 0.11, byteLength is an own nonconfigurable property