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/loupe/lib/regexp.js

@@ -0,0 +1,8 @@
+import { truncate } from './helpers'
+
+export default function inspectRegExp(value, options) {
+  const flags = value.toString().split('/')[2]
+  const sourceLength = options.truncate - (2 + flags.length)
+  const source = value.source
+  return options.stylize(`/${truncate(source, sourceLength)}/${flags}`, 'regexp')
+}