Performance degradation fix

I've been using Dance quite a lot recently, but sometimes it started to lag excessively, particularly after I would trigger a conflict between code and dance handling the cursor. I'm not keen on delving into a lot of typescript and I'm not familiar with the vscode extension model, so I just asked Claude to look around for possible causes. The `===` -> `=` looks like a legit mistype, but I have no clue about the rest. My limited testing for now makes me think that it solved the issue; can somebody with experience with the codebase chime in and review it? The first commit should directly address the issue, the second one is more things there were found. Probably fixes https://github.com/71/dance/issues/343#issuecomment-2308740744 (or #343 altogether)