fba21ad5a6
run.py refuses to start if --log-dir already exists (interop.py:81-82 calls sys.exit). Previous script eagerly mkdir'd $LOG_DIR, which made the second run always fail. New layout: $LOG_DIR is the parent (created if missing), each invocation writes to $LOG_DIR/run-YYYYmmdd-HHMMSS/. Preserves history of past runs instead of overwriting; latest is `ls -t $LOG_DIR | head -1`. https://claude.ai/code/session_01HcvfQq1ttPV9PkRoJb4nyT