CLI tells user when their installed CLI version is current or not

[lasomethingsomething]

User story

As a dev, I want the CLI to tell me whether my installed version is current or out of date when I run it, so I know where I stand.

Entrypoint story that would eventually lead up to #932.

Implementation

• user through their package manager checks every seven days for the latest version; on mac use brew upgrade, linux use apt upgrade
• on a daily basis, user gets reminder to update version
• add an opt-out option to reduce noise

Acceptance criteria

• Ensure the message is prominently displayed and optimally visible to the user
• TUI top-right, next to docs and GitHub links, display a red tag/warning

Readiness checklist

• Acceptance criteria are clearly defined.
• Backward compatibility impact addressed.
• Documentation written.
• Tests added or adjusted accordingly.