Linchpin

Hand it a folder of PRDs and it builds them. Each PRD runs in its own git worktree, so lanes work in parallel without stepping on each other. When a lane finishes, a separate reviewer model checks it in a read-only process, and delivery is gated on the checks the PRD itself asked for. The model that writes the code is never the model that approves it. You get a report of what shipped, what is blocked, and the command to resume anything unfinished.