Mirrors the palette/part-override mapping at GameWindow.cs:3390-3431 in a
testable static helper. Build() accepts plain (SubPaletteId, Offset, Length)
and (PartIndex, GfxObjId) tuples, builds PaletteOverride only when
subPalettes.Count > 0 (same gate as GameWindow), and poses the entity at
origin facing the viewer (191.367905° / +Z). Reserved synthetic guid
0xDA11D011 keeps the doll distinct from the live player and satisfies
EntitySpawnAdapter's ServerGuid != 0 guard. 7 new tests green; suite 594/0.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>