Add source selection and collision review to setup workstation

[rmanibus]

Summary

Continue RFC 0014 by adding an interactive review step to cloudstic setup workstation.

Scope

• allow users to skip suggested sources instead of always creating every draft
• review existing-profile collisions before writing
• support update, rename, and skip decisions during setup review
• reflect reviewed choices in the final workstation coverage summary
• keep -dry-run as a preview path and -yes as non-interactive acceptance

Notes

This slice builds on the existing workstation plan/apply flow. It should stay focused on review and selection rather than redesigning the entire onboarding command surface.

Parent RFC/epic: #130