“Do Diffinity” button does not appear on GitHub PR pages

[maantano]

Description

The extension installs correctly and the popup/settings UI works, but the “Do Diffinity” button never appears on GitHub PR pages.

I checked the console and found that the selectors used by the extension seem to return null on the latest GitHub UI:

document.querySelector(".gh-header-actions")

This suggests the extension may depend on an older GitHub DOM structure.

No console errors are shown, but the button is never injected into the page.

[developerjhp]

@maantano
Great catch on the selectors! Since you've already identified the cause, would you be interested in contributing a fix for this? I'd be happy to review and merge your PR.