Rewrites 14 materials from the removed sbsar sub-assets to Assets/Materials/PBR
textures (Steel_Brushed, Gunmetal_Dark, Metal_Scratched, Paint_Worn_Light,
Plates_Panels), keeping each sbsar preset colour as _Color where it differed; flat
colour for Discobolus Marble (no marble set ships). Adds Pickup Trim.mat (copy of
Car Paint White Small, flat trim colour). Turret, the five pickup prefabs and the
Zenith_Blender externalObjects now name file materials instead of the ProceduralMaterial
sub-asset. Own commit so it reverts alone (question sbsar-fallback-fidelity, built on
its recommended option; no ruling yet).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>