A copy leaves the tab whole: beside the mention tokens, an HTML clipboard
flavor carries the timeline items and the assets they play, or a copied
card's asset. A paste in another project, on Mac or Windows, brings the
media across from wherever that project lives, remembers where each copy
came from so the next paste finds it, and lands the items the way a
same-project paste does. Caption cues copy and paste with the rest. The
item-kind table is walked by a test so every kind proves it copies,
pastes and crosses a project.

Claude-Session: https://claude.ai/code/session_014g9WuMAv9p5Db8cYzs1tjQ