Each enrollment scope owns its panels, ports and temp dirs, so the two run
side by side; the only shared state, the process-global database handle the
harness borrows for setup and for simulating a lost inbound, is now behind a
mutex. On Linux the suite drops from 188s to 95s.
CLAUDE.md now names the fast contract layer (node_contract_test.go, in
make test-go) next to the multi-tick nodee2e layer.