fix: restore customDomain field in getCurrentUser query fragment (#17949)

## Summary
- The `customDomain` field was accidentally removed from the
`currentWorkspace` GraphQL query fragment in #16016 (Nov 2025), when
`workspaceCustomApplication { id }` was added in its place rather than
alongside it.
- This caused the custom domain settings page to never display the
configured domain value, the reload/delete buttons, or the DNS records —
since `currentWorkspace.customDomain` was always `undefined`.
- Restores the missing field in the query fragment.

## Test plan
- [ ] Navigate to Settings > Domains on a workspace with a custom domain
configured
- [ ] Verify the custom domain value appears in the input field
- [ ] Verify the Reload and Delete buttons are visible
- [ ] Verify DNS records are displayed


Made with [Cursor](https://cursor.com)

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/twenty-front/src/modules/users/graphql/fragments/userQueryFragment.ts

@@ -59,6 +59,7 @@ export const USER_QUERY_FRAGMENT = gql`
       isMicrosoftAuthBypassEnabled
       isPasswordAuthBypassEnabled
       subdomain
+      customDomain
       hasValidEnterpriseKey
       workspaceCustomApplication {
         id