Reads a project's timeline structure: timelines (id, name, fps, resolution) with tracks and clips. THE USER CAN COPY A CLIP'S ID from the editor's right-click menu, so a bare UUID in their message names exactly one clip — call this with NO timelineId to search every timeline and match clip.id, rather than guessing from a name. Clips carry id, name, mediaRef, kind, startFrame, endFrame (exclusive), trimStartFrame and linkGroupId (linked A/V pairs share it), plus look (opacity, blend, transform, crop, keyframes) whenever any of it differs from the defaults — an untouched clip has no look key. Omit timelineId to get every timeline; frames are in that timeline's fps.