Completes step (c)'s convention-convergence: commands were migrated to skills
in upstream v2.39.0. Local essay-* commands now live as skills with the ce-
prefix. commands/workflows/{plan,review,work}.md predated ce-plan/ce-code-
review/ce-work and are now redundant — deleted.
Remaining in commands/: pr-comments-to-todos (retool in step g) and
resolve_todo_parallel (delete in step f).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>