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/utils.js

@@ -0,0 +1,11 @@
+export const identity = value => value;
+
+export const noop = () => undefined;
+
+export const getContentsProp = ({contents}) => contents;
+
+export const throwObjectStream = chunk => {
+	throw new Error(`Streams in object mode are not supported: ${String(chunk)}`);
+};
+
+export const getLengthProp = convertedChunk => convertedChunk.length;