The bottom play/pause button did nothing. The gesture listener lives on
the outer container and touch events bubble, so tapping the button ran
handleTouchStart (toggle #1) and then the button's own onclick (toggle
#2). The two cancelled out, leaving the control apparently dead.
Ignore container-level gestures for touches that land on an interactive
control: buttons, links, inputs (the seek bar), or anything inside the
controls bar, now marked `data-player-controls`. The rule itself is a
pure function over the ancestor chain (isControlSurfaceTouch), so it is
unit tested without a DOM.
Same root shape as the play-overlay bug in the previous commit: a second
click target over the video that the gesture layer did not account for.