Release playbook

The release playbook shared by every crafting app lives in craftrules: ../craftrules/release/playbook.md (storytold/craftrules, a sibling checkout; the repository is not public). It is the canonical copy; don't duplicate it here.

Picto is its reference implementation (.github/workflows/release.yml, packaging/, cargo xtask version). Picto-specific details are in releasing.md.