[WIP] Fix keyboard arrow navigation through Otter blocks on WP

[Codex]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

---

This section details on the original issue you should resolve

<issue_title>Navigating through Otter blocks using keyboard arrows on latest WP</issue_title>
<issue_description>### Description

I'm not sure if this is an issue from core or is there something to do from Otter.
Navigating using keyboard arrows doesn't work as before WP 7.0. I've tried to showcase in the video
https://github.com/user-attachments/assets/89f7efa3-91a1-4ff7-b107-c08fcabd7ad8

Step-by-step reproduction instructions

https://secure.helpscout.net/conversation/3333301161/490282

Screenshots, screen recording, code snippet or Help Scout ticket

No response

Environment info

No response

Is the issue you are reporting a regression

No</issue_description>

<agent_instructions> Moving through block structure with keyboard arrows does not work.
Full widith block does not work.
Maybe more but I'm frustrated enough to look for it. 2. Keyboard Navigation
Regarding the arrow key navigation, this behavior stems from core architectural changes introduced in the latest WordPress release. It currently impacts standard WordPress core blocks as well, not just Otter. I will share this with the development team for review to see if there is something that can be done from Otter's side.</agent_instructions>

Comments on the Issue (you are @codex[agent] in this section)