errors in bottom panel are collapsible

src/App/PersistentDetails.tsx

@@ -0,0 +1,15 @@
+import { usePersistentState } from "@/util/persistent_state"
+import { DetailsHTMLAttributes, PropsWithChildren } from "react";
+
+type Props = {
+  localStorageKey: string,
+  initiallyOpen?: boolean,
+} & DetailsHTMLAttributes<HTMLDetailsElement>;
+
+// A <details> node that remembers whether it was open or closed by storing that state in localStorage.
+export function PersistentDetails({localStorageKey, initiallyOpen, children, ...rest}: PropsWithChildren<Props>) {
+  const [open, setOpen] = usePersistentState(localStorageKey, initiallyOpen);
+  return <details open={open} onToggle={e => setOpen(e.newState === "open")} {...rest}>
+    {children}
+  </details>;
+}