The extensions API lets you control the sidebar, but you basically don't have control over anything in the editor. We wouldn't have been able to build our inline edit feature, or our navigation UI if we were an extension.
Big fan of Continue btw! There's a small difference in how we handle inline edits - if you've used inline edits in Cursor/Windsurf/Void you'll notice that a box appears above the text you are selecting, and you can type inside of it. This isn't possible with VS Code extensions alone (you _have_ to type into the sidebar).
If I understand your question correctly - Cline and Roo both display diffs by using built-in VS Code components, while Cursor/Windsurf/Void have built their own custom UI to display diffs. Very small detail, and just a matter of preference.
It's about whether the tool can edit just a few lines of the file, or whether it needs to stream the whole file every time - in effect, editing the whole file even though the end result may differ by just a few lines.
I think editing just a part of the file is what Roo calls diff editing, and I'm asking if this is what the person above means by line edits.
