gamedata+docs: confirm force-resend mechanism identical on Windows

Windows WriteDeltaEntity_Internal (engine2.dll 0x1800d1240) verified to use the same
serializer singleton (DAT_1806858a0) + vtable slot 8 (+0x40 CalcDelta) + slot 14
(+0x70 WriteFields) + two-path build as Linux. Added the Windows global-load sig to
CNetworkSerialization::SerializerSingleton (MOV RCX,[rip]; +3 r). Force-resend hook +
sorted-insert is cross-platform unchanged.

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