A failing Assert.DoesNotContain/Contains over a collection of Entities made xunit format the Entity graph and overflow the stack, aborting the host; the five such assertions now assert a bool. Adds a docked-subject stance test and a pending-paint-on-leaving test. Builds: yes (test-only).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>