010 T4: Withdraw #485 (in-thread reply), tidy #494 nf-z15o ← Beads

Twinned from https://github.com/cfsh/ninefold/issues/1004 by tools/beads/import_github.py's reconcile pass.

From 010-co-located-tests-and-probes.md's task table (design 010). - Real dependency: T2 - Note: bookkeeping; #494 fully closes with T6