A failed MovingCircle.advance now calls the owner hook, so the Simulation is marked failed (Jet lifecycle) and refuses run/step/sync until close(). Adds host tests for set_body routing on real objects, initialize band and mode rejections before mutation, exclusion from static link packing, and the Simulation failure lifecycle. Contract status line updated for S1. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>