keyframe-animation: start on image A, end on image B, fill in the middle

Two stills you already have become one clip: image A is attached as the first frame, image B as the last frame, in the same job, and the model generates the motion between them.

This skill is a thin, scenario-specific layer over ofox-video-core. It owns what makes a usable A/B pair, the prompt for the middle, the duration advice, and the pre-generation cost estimate; ofox-video-core owns talking to the Ofox API correctly and safely (the OFOX_API_KEY handling, the no-resubmit rule, error-code mapping, download/verification, and reporting the downloaded file's absolute VIDEO_PATH). Read that skill's safety contract before using this one — it is not restated here.