The host region was the ONE arena-plan term still autofitting per boot: with
no cap the planner binds it to MemAvailable AT BOOT minus PLE/process/api/
margin terms (boot 2026-10-05: 237.97 GiB -> 159.39 GiB usable; the same host
reads 75.4 GiB available while running). Demand is 105.48 GiB
(52.74/rank x 2 ranks, 23,040 swap-target experts); a boot where co-tenant
RAM squeezed the bound near that silently pins next-hottest experts VRAM-only
(pinned_extra warning, smaller swap region, no flag change). 120 GiB =
measured demand + 14% headroom on 246.1 GiB total. Semantics verified in the
shipped image: cap binds as the bound, exceedance only warns.
The GPU-side arena is unchanged (deterministic arithmetic over the same
constants): verify after boot that host reads '--expert-offload-mem' and
slots stay 7,762. Seam: red first (wiring + value), then green; full suite
368+1 green.