pr-body

Use when you are about to open a pull request, edit a pull request description, write a PR summary, or update the proposed squash-commit message on an existing PR. Defines the silk-release marker contract that lets humans, local agents and cloud agents share one PR description without overwriting each other: which regions you own, which are regenerated, and the two incompatible spellings of a closing reference. Triggered by "open a PR", "gh pr create", "gh pr edit", "write the PR description", "update the PR body", "link the issues on this PR". Covers the DESCRIPTION only; the PR title and a proposed-squash-commit fence belong to the commit-create skill.