Keep pumping the event loop past the general 500ms settle limit only while the dynamic-script queue remains pending, with a 3s hard cap.
Add a deterministic CDP regression for direct and nested external scripts whose fetch crosses the original settle deadline.
Move fragment children into the target for appendChild, insertBefore, and replaceChild while preserving their order and emptying the fragment.
Add runtime regression coverage for the DOM attachment portion of #452.
lisa0314