story-video-prep 是做什么的？
Build a short (~15-40s) animated "story video" as a single self-contained HTML file — kinetic typography on a cinematic ground, with the brand logo and a royalty-free music track embedded (trimmed + faded to the cut, beat-synced). Use when the user wants a promo / brand / campaign / launch / explainer / "sizzle" video, a video for an email or landing page, or says "make a video / a short film / a story cut / an animated intro." Produces a self-contained playable HTML, and renders it to a real MP