Salvage of PR #1246 by ChatGPT (teknium1 session), resolved against
current main which already includes #1239.
Changes:
- Add minisweagent_path.py: worktree-aware helper that finds
mini-swe-agent/src from either the current checkout or the main
checkout behind a git worktree
- Use the helper in tools/terminal_tool.py and mini_swe_runner.py
instead of naive path-relative lookup that fails in worktrees
- Clean up check_terminal_requirements():
- local: return True (no minisweagent dep, per #1239)
- singularity/ssh: remove unnecessary minisweagent imports
- docker/modal: use importlib.util.find_spec with clear error
- Add regression tests for worktree path discovery and tool resolution
