3D version of the refined PR map: 25 ownership lanes by 17 product/runtime flows. Each PR is a flat file-dot cluster pinned at its update time; color is author; z is time. The PR-to-PR curves cross time to trace a line of work: threads (a named line, e.g. better-auth migration), FE↔BE pairs, mentions, and tensions (open PRs with conflicting design). Faint file overlaps are hidden until you toggle "Overlaps".