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/get-stream/source/buffer.js

@@ -0,0 +1,20 @@
+import {getStreamAsArrayBuffer} from './array-buffer.js';
+
+export async function getStreamAsBuffer(stream, options) {
+	if (!('Buffer' in globalThis)) {
+		throw new Error('getStreamAsBuffer() is only supported in Node.js');
+	}
+
+	try {
+		return arrayBufferToNodeBuffer(await getStreamAsArrayBuffer(stream, options));
+	} catch (error) {
+		if (error.bufferedData !== undefined) {
+			error.bufferedData = arrayBufferToNodeBuffer(error.bufferedData);
+		}
+
+		throw error;
+	}
+}
+
+// eslint-disable-next-line n/prefer-global/buffer
+const arrayBufferToNodeBuffer = arrayBuffer => globalThis.Buffer.from(arrayBuffer);