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/strip-final-newline/index.js

@@ -0,0 +1,14 @@
+export default function stripFinalNewline(input) {
+	const LF = typeof input === 'string' ? '\n' : '\n'.charCodeAt();
+	const CR = typeof input === 'string' ? '\r' : '\r'.charCodeAt();
+
+	if (input[input.length - 1] === LF) {
+		input = input.slice(0, -1);
+	}
+
+	if (input[input.length - 1] === CR) {
+		input = input.slice(0, -1);
+	}
+
+	return input;
+}