Point the paint variant keep-alive at the right shader

The painter clones Player.mat (Custom/PlayerCamoLit) at runtime and enables
_METALLICSPECGLOSSMAP, _EMISSION and _OCCLUSIONMAP, all shader_feature_local.
That keyword combination existed on no PlayerCamoLit material at build time,
so Unity stripped the variant and the build fell back to the base variant -
metallic/smoothness/emission/occlusion ignored, giving the flat look. The
keep-alive material that should pin this variant pointed at URP/Lit instead
of PlayerCamoLit, so it kept the wrong shader alive. Swap its shader GUID to
PlayerCamoLit; the three keep-alive keywords already match what the painter
sets, so the needed variant is now pinned into every build.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/Resources/PaintVariantKeepAlive.mat

@@ -21,7 +21,7 @@ Material:
   m_PrefabInstance: {fileID: 0}
   m_PrefabAsset: {fileID: 0}
   m_Name: PaintVariantKeepAlive
-  m_Shader: {fileID: 4800000, guid: 933532a4fcc9baf4fa0491de14d08ed7, type: 3}
+  m_Shader: {fileID: 4800000, guid: 7b3dd5720b6152047b45788060d64904, type: 3}
   m_Parent: {fileID: 0}
   m_ModifiedSerializedProperties: 0
   m_ValidKeywords: