Fix tournament sub form crash

app/features/tournament-subs/routes/to.$id.subs.new.tsx

@@ -11,6 +11,7 @@ import { WeaponCombobox } from "~/components/Combobox";
 import { FormMessage } from "~/components/FormMessage";
 import { WeaponImage } from "~/components/Image";
 import { Label } from "~/components/Label";
+import { RequiredHiddenInput } from "~/components/RequiredHiddenInput";
 import { SubmitButton } from "~/components/SubmitButton";
 import { TrashIcon } from "~/components/icons/Trash";
 import { useUser } from "~/features/auth/core/user";
@@ -267,7 +268,11 @@ function WeaponPoolSelect({
 
 	return (
 		<div className="stack md sub__weapon-pool">
-			<input type="hidden" name={id} value={JSON.stringify(weapons)} />
+			<RequiredHiddenInput
+				isValid={!required || weapons.length > 0}
+				name={id}
+				value={JSON.stringify(weapons)}
+			/>
 			<div>
 				<Label htmlFor={id} required={required}>
 					{label}