Tabs for multiple open notes

[yhat-penguin]

I’d like to suggest adding tab support for multiple open notes, similar to how modern code editors or browsers handle tabs.

Currently, switching between notes requires using the sidebar, search, or back/forward navigation. When working on multiple related notes (documentation, research, project planning, etc.), this creates friction.

Thanks for considering it, and great work on keeping FSNotes fast, native, and efficient.