1. Check for an existing project-local skill (`trellis-local`).
2. If it doesn't exist, create a new `trellis-local` skill.
3. Document the base Trellis version and initialization date in the `trellis-local` skill.
4. For every modification to Trellis, record the changes in the `trellis-local` skill, including the file modified, the purpose of the change, the date, and the reason.
5. Never modify the `trellis-meta` skill for project-specific changes.
6. When upgrading Trellis, compare the `trellis-meta` skill with the new Trellis version and update the `trellis-local` skill accordingly.