I'd recommend Obsidian. Free and perfect for making and organising markdown notes, plus heaps of community extensions. And out-of-the-box you can make "canvas" pages where you can draw diagrams.

I'm interested to know more about what you mean by this.

Kagi

Couple of ideas: At the end of the first quarter they were originally going to release the alpha for their Cosmic DE which got postponed. They also had the LinuxFest NorthWest conference they presented at.

Reminds me of the surprised Pikachu meme

iHole

This looks to be closest

Your best bet is on their feedback forum here. There's a good chance someones requested the feature you mentioned, in which case you'd be better off voting it than creating a new one.

Just looked this up, had no idea but it makes sense

Thanks for the laugh

GPT Unicorn is one that's been going on a while. There's a link to the talk on that website that's a pretty good watch too.