Codex App Compatibility: Worktree and Finishing Skill Adaptation

Make superpowers skills work in the Codex App's sandboxed worktree environment without breaking existing Claude Code or Codex CLI behavior. Ticket: PRI-823 The Codex App runs agents inside git worktrees it manages — detached HEAD, located under $CODEXHOME/worktrees/, with a Seatbelt sandbox that blocks git checkout -b, git push, and network access.