[MetaROR] Ch10 Checklist — author revisions

[LukasWallrich]

Author revisions for Chapter 10 (Checklist) from the MetaROR reviews (R1).

• Reconsider the checklist format — items are currently high-level recommendations rather than concrete checklist items. (R1) (in Make checklist items concrete and actionable (#23) #43)

Handled in other issues:

• Move the checklist to an Appendix and discuss it in a conclusion section rather than its own Part → Structural reorganisation & scope