Planning only; no source files touched. The BFS visited set in exploreMoves
keys on (coord, entry), so two legal routes that rejoin through the same port
collapse to whichever is shorter — silently discarding the option that couples
cars on the way.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YQAJ4dND7enLj54eLyiF2C
