git is reading a bad worktree path from .git/config:
- core.worktree points at /private/var/folders/.../agents-claude-sync-g123
- that is not your current checkout at /Users/dlo/work/dennislo.github.io
So Git thinks the repo’s working tree is somewhere else, and checkout fails.
Fix it with:
git config --local --unset core.worktree
# or, if you want it explicit:
git config --local core.worktree /Users/dlo/work/dennislo.github.io
Then retry:
git checkout develop