Simulates orchestrator-leaked CWD in the post-merge cleanup loop and
asserts that PROJECT_ROOT is resolved via `git -C "$WT" rev-parse
--git-common-dir` before any bare git command, that a missing root
causes a logged skip/continue, and that the existing pre-merge deletion
guard (#1756) and STATE.md/ROADMAP.md backup/restore remain in-place
after the CWD pin.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
