Draft: super topbar

What does this MR do and why?

🚧 WIP! Adds global topbar *** Still looks broken at the moment *** Will update screenshots and description as I go. Not a stable branch yet! WIP! 🚧

References

Screenshots or screen recordings

recording_1753972557664

How to set up and validate locally

Enable the global_topbar feature flag.

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.