Improve the highlight to edit frontend UX

[bracesproul]

The highlight to edit feature can be a little janky. I would like to have the following improvements made to it:

• Ensure the Ask Open Canvas input never shows up if text is highlighted outside of the code/markdown renderer.
• Allow users to trigger it when they select using the keyboard (cmd + shift + arrow, etc.). Right now it is only triggered by selecting with a mouse.
• Disable code string match highlighting. The code editor has a feature where you can select strings and it will highlight all occurrences in the file (like an IDE does). Let's disable this.
• Improve the Ask Open Canvas UI in both the code and markdown renderers. (if possible, use the actions menu which pops up when you select text in the markdown editor. This is currently disabled because the formattingToolbar={false} prop is passed. Ideally we can overwrite the contents to contain an Ask Open Canvas input, and a B + I (bold/italic) button).
• Improve the UX to include a smooth transition when you click Ask Open Canvas and it transitions into an input component.

These should all be done as separate PRs. If you want to take one on, please leave a reply and I will create a new issue for that task and assign it to you.

[ahmad2b]

Hey @bracesproul! 👋

I've submitted PR #187 tackling the first UX improvement from your list - ensuring AskOpenCanvas respects renderer boundaries. The implementation is thorough with strict validation and clean state management.

Moving forward with the remaining tasks.

I'll keep the same pattern of isolated PRs for each task to maintain clean review cycles. Looking forward to your feedback on the current PR!