segment_value treated any non-Linear in-side of the next key as Bezier,
so a key set to Hold (KeyframeInterpolationType.HOLD, add_keyframe
"interpolation": "hold", or the Keyframe Interpolation dialog, which set
both sides) turned the linear segment into it into an ease-in with the
default ease: 0 -> 100 over 2 s read 27.0 instead of 25 at 0.5 s. Hold
only affects what follows the key, which the out side already handles.
The Graph Editor and the Lottie exporter already treat a Hold in-side as
linear, so exports didn't match the preview either.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
