Review B4: the Stormwind window split changed the default image with no switch.
New cvar daylightWindowSplit (default 1 = merged behaviour, a future High-only
preset member), bridged to daylight::set_window_split. Review B5: each settled
exterior torch slot is keyed by the resident tiles whose footprint reaches its
sphere (terrain_torch_generation_near), not a global stamp that re-rendered
every slot on any stream event.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
