fix(dns): reset add nameserver dialog on close

Closes #635.

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Fixes
 
 - Fixed several broken actions (such as creating auth keys) that began failing with "Bad Request" or "Unexpected Server Error" after Headplane 0.8.0 when sitting behind a reverse proxy that terminates TLS. If you added a proxy rule rewriting the `Origin` header as a workaround, it's safe to remove (closes [#657](https://github.com/tale/headplane/issues/657), [#658](https://github.com/tale/headplane/issues/658)).
+- Fixed a bug where the **Add nameserver** dialog would not show the **Restrict to domain** switch in the correct state when closing and reopening the dialog after adding or canceling a split DNS nameserver (closes [#635](https://github.com/tale/headplane/issues/635)).
 
 # 0.8.0 (October 13, 2026)
 

app/routes/dns/dialogs/add-ns.tsx

@@ -45,7 +45,7 @@ export default function AddNameserver({ nameservers }: Props) {
   const split = (form.values.split_name as string) !== "global";
 
   return (
-    <Dialog>
+    <Dialog onOpenChange={(isOpen) => !isOpen && form.reset()}>
       <Button>Add nameserver</Button>
       <DialogPanel>
         <Title className="mb-4">Add nameserver</Title>
@@ -73,6 +73,7 @@ export default function AddNameserver({ nameservers }: Props) {
           </div>
           <Switch
             label="Split DNS"
+            checked={split}
             onCheckedChange={(checked) => {
               form.setValue("split_name", checked ? "" : "global");
             }}