test: four hyperspace crew classes share one client instead of four

- the transit probe hands each scenario a fresh pool cell, so its gates already scope
- three of the four @after cleanups only redid what the shared reset asserts
- render distance moves into the reset, not an @after the watcher runs after
- one class keeps its own envelope-reading exec rather than the joining one
- the ring-frame baseline is taken inside the corridor, not on the crossing frame

Author: StannisMod