A suite run from an agent pane with --basetemp .../pytest-pr56-shim left seven workspaces on that pane's real server (multi-agent-mux): - the real-herdr resolvers (lib.sh _is_shim_path and the generated shim) skipped every PATH directory with "-shim" anywhere in its path, so the basetemp hid the mock's bin/ and the real herdr ran; only a directory that is itself *-shim is a wrapper now; - mam_sandbox kept HERDR_SOCKET_PATH (and the pane/tab ids), which the real herdr follows over the sandbox HOME; it drops them now. tests/test_herdr_real_server_leak.py: L1 (ancestor *-shim, both resolvers) and L2 (pane routing dropped) fail before the fix; L1b keeps a *-shim wrapper directory excluded. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff