At N>=2 a cheap-window maintenance charge files a site `hi` (`charge`,
P_MAINT_SHAPE) equal to what the charging pack's own `hi` places, so the
other pack never has to give against it. The charge is sized to the
quarter's headroom under the peak aim so it yields to the peak guard, and
to 0 W under a site safety stop. N=1 byte-identical (safety84_identity).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
