[Todo] Debounce dark mode to prevent weird color bugs

[zaydek]

For this one we need to add a flag to the runtime (src/runtime/runtime.ts) that prevents the dark mode shortcut (ctrl-d) from being rerun while the dark mode transition is active. So we need to add a kind of #darkModeInProgress variable to the class. Then the dark mode functions needs ask whether dark mode is in progress; if dark mode is already in progress, do nothing (return early), otherwise run normally.

Something like this:

if (#this.darkModeInProgress) {
  // No-op
  return
}
// ...

Then we’ll probably want to add a test for this in tests/runtime that makes sure this is working as expected. That might be a little tricky so I can help you with that if you need.

[zaydek]

This is part of #265. I just need to write tests to verify this works as expected.