Evidence-Backed Living PRD Generator

Create compact PRD file(s) that are grounded in the existing system, explicit enough for a junior developer or fresh AI agent to execute, and structured as a living source of truth. Work is checked off in the PRD, later phases are revised as implementation reveals new information, and every phase ends with structured validation and review.

Do not implement the feature unless the user explicitly asks. This skill creates or updates PRD, context, and phase files only.