Edit admin page missing padding

#### Steps to Reproduce
1. Go to `/wp-admin/admin.php?page=polls`
2. Click on Edit for a poll
4. See error

#### What I Expected

Layout of the Edit page in wp-admin would look like a regular page, and not crash into the sides of the container.

#### What Happened Instead

The layout crashed into the edge of the admin menu and the edge of the browser window.

#### PHP / WordPress / Crowdsignal version

2771eae9dbdbc64576ff1b32ae020c388d868c81 on `develop`.

#### Browser / OS version

Chrome (latest) on MacOS 26

#### Screenshot / Video

#### Context / Source

I notice that the checkboxes in the Save meta box are also missing some padding, so all of the markup probably needs checking for this admin page to match up with how wp-admin has been updated.

Start from the /wp-admin/admin.php?page=polls edit-page flow in the develop revision and inspect the admin page markup and styles around the container and Save meta box. Compare its spacing with the surrounding WordPress admin layout; done means the Edit page and its checkboxes have consistent padding without touching the menu or browser edges.

Written by the indexing model from the issue text.