Structured, stateful plan files

Convention for plans/YYYY-MM-DD-topic.md — one file per idea or design, a YAML frontmatter status field so its lifecycle is visible without opening it, and a firm rule that plans/ stays a working set, not a permanent archive.

Rationale, prior art, and worked examples: references/design-rationale.md. Whether an existing tool should have been adopted instead — the markdown task trackers, git-bug, beads, and why cross-repo is the case none of them solves cheaply — is references/prior-art-task-trackers.md.

What this skill reads, runs and writes