[DNM] Introduce lexical to improve textarea (better context mention UX, no more hacks with regex, etc)

[elianiva]

it's still in a very rough condition, but basic text editing works for now
just putting this up to let people know and avoid duplicate effort

todo:

• basic text editing
• properly handle keyboard events
• handle commands (currently only used to change mode, but we can expand the idea further)
• handle copy/paste for files
• handle drag and drop
• handle mention (file, commits, etc)
• display mention in a better format
• show included context in current prompt
• other edge cases i haven't found yet
• add tests, there's currently none

a lot of these are generated by gemini 2.5 pro as you can tell by a lot of these useless comments, i've adjusted a few of them but there are still a lot of stuff that needs to be fixed ((it was struggling with apply_diff a lot once it reaches a certain point i ended up stopping it and just do it by hand))

i'll be adjusting/fixing them along the way and posting updates here (and discord)

feel free to comments any of your ideas :)

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[cte]

Nice! I noticed that they have a mentions plugin; should we use that or roll our own?

[elianiva]

Nice! I noticed that they have a mentions plugin; should we use that or roll our own?

currently i want to try to roll our own because i want to experiment a bit with it, having more control is good