The PPTX import numbers shapes per slide, so two slides can hold different
videos under one shape id. find_clip searched the whole deck and took the
first match, so the show's media cues, the keep-across-slides filter and
the media.* requests all got the first slide's clip: from slide 3 on, video 2
played. find_clip now takes the slide the request comes from and searches it
first, then the rest of the deck.
Co-Authored-By: Claude <noreply@anthropic.com>