refactor: split frontend application features

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/components/actions/ErrorAlert.tsx

@@ -0,0 +1,19 @@
+export function ErrorAlert({
+  message,
+  retry,
+}: {
+  message: string
+  retry?: () => void | Promise<void>
+}) {
+  return (
+    <div className="error-alert" role="alert">
+      <strong>Request failed</strong>
+      <span>{message}</span>
+      {retry && (
+        <button type="button" onClick={() => void retry()}>
+          Try again
+        </button>
+      )}
+    </div>
+  )
+}