Post-yield now also reaps init-adopted (`ppid==1`) tractor procs
that appeared during the test — leaked subactors whose mid-tier
parent died during cascade teardown, reparenting them to init.
Pre-yield snapshot of existing orphans scopes reap to THIS test's
leaks only, avoiding reap of unrelated tractor uses (piker, etc.)
on the box.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code