VM.running_on claimed by compare-and-swap on switch-in and released once
the context is saved (release_after, sk_vm_switch_finish); a lost claim
returns 1 and the caller re-decides; double claims counted. Per-core
entry_vm and decision_due. g_lock_physics over capsule_vm_physics.c
(rank between switch and registry). KILL refuses a VM running anywhere.
Probe: 15737 claims, 0 lost, 0 double; a core-1 claim of Hera refused.
3-ISA acceptance with a 28-VM churn clean, 0 order violations.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
