Function decodeMLeaderStyleRawColor

Decodes MLEADERSTYLE DXF raw-color int32 to AcCmColor.

Raw-color is a packed 32-bit signed integer:

• high byte (bits 24-31): color type flag
• low bytes: payload

Why values often look negative:

• DXF stores this as signed int32; high-byte flags >= 0x80 become negative decimals.

Algorithm sources:

• AutoCAD DXF MLEADERSTYLE docs (group codes 91/93/94): https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-DXF/files/GUID-0E489B69-17A4-4439-8505-9DCE032100B4.htm
• ezdxf reference implementation (decode_raw_color_int): https://raw.githubusercontent.com/mozman/ezdxf/master/src/ezdxf/colors.py