An animated WebP used to bring only its first frame into a video layer. Now
New Video Layer from File, Replace Footage, Reload Frame and Video Frames to
Layers take every frame, as they do for an animated GIF (#572):
- photocraft-codecs: `decode_webp_frames` returns each frame composited onto
the canvas by image-webp (offsets, blending, disposal), with its duration in
milliseconds and the file's ICC profile. A still WebP is one frame, read as
`decode` reads it. A damaged later frame keeps the frames before it and marks
the first `Truncated`; the frame count and total bytes are checked against
`Limits`. `webp_is_animated` tells the two apart. New `decode_webp` fuzz
target.
- photocraft-io: `import_webp_frames`, sharing `import_gif_frames`' loop.
- photocraft-engine: `load_frames` takes an animated WebP's frames; the
timeline rate comes from the most common duration. A still WebP keeps the
existing path and the 30 fps default.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
