get_segmentsList the storyboard's segments (narration span, type, duration, creative
direction). The 1-based segment_number is the handle every segment tool takes
(update/split/combine/continuation/regenerate) — you never need a UUID.
Each segment also reports `continues_from_segment`. When set, this shot is a
CONTINUATION of that earlier segment: its rendered frame carries over (same
composition, characters, and setting) and only the delta changes — an added
overlay, a shifted expression, a closer angle, a slow reframe. Null means a
fresh, independent shot. The storyboard plans these chains automatically;
adjust them with set_segment_continuation.