build-unity-package.ps1 read the bridge's file names to decide whether it
re-declared core CultMath sources. It now parses declarations: core type
names come from src/CultMath (comments stripped), and every bridge source may
declare types only in CultMath.UnityBridge and never a core type name.
Probed by injecting "struct float3" into UnityConversions.cs: the script
throws.
Strips the UTF-8 BOMs this branch added to both Unity package.json files.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>