Reimplement the immediate synchronization hash command

[Krarilotus]

Reimplements the message that players use to exchange their synchronization hash, lag and match time. Sending reads the local player's values; receiving updates the resolved sender's values so the game's existing synchronization checks can use them.

CommandCheckSync at SHC 0x480B10 declares a ten-byte immediate command and uses the fixed parameter buffer. Preserve the native field order (2-byte lag, 4-byte hash, 4-byte match time), actor selection, and the size/timestamp-only behavior during received scheduling or unknown phases. This PR adds one readable C++03 implementation using the existing resolvers.

Validation:

• The normal full OpenSHC.dll CMake build now passes with MSVC 2005 SP1 and a Microsoft-signed Windows SDK manifest tool. This resolves the earlier bundled mt.exe crash; the DLL has its embedded manifest and no deployment was performed.
• All 203 function bytes match the original SHC body after binding resolver references to native addresses. Mapping Extreme's two player-field offsets and native addresses also gives a 203-byte match against its original body.
• 1,280 native serializer/phase/player/ring/cursor cases per variant pass, including stack and nonvolatile registers. Only the low-level memory-copy body is a stand-in; the command and serializer use native instructions. Supplementary investigation tooling remains local.
• Linked reccmp reports 75.47%, with unmatched global/serializer resolver identities. The normalized byte comparison above is distinct from that linked score; this is not a claim that the whole DLL is byte-identical.

This does not implement hash generation, resynchronization, Steam transport or multiplayer replay. The implementation was checked against the existing Ghidra database and original executables while investigating immediate-message capture in the recorder. Based on current upstream main; generated headers and resolver activation flags are unchanged.

[Krarilotus]

The build limitation is resolved: the normal full OpenSHC.dll target now passes using the existing MSVC2005 SP1 compiler and a Microsoft-signed Windows SDK manifest tool. All 2,560 original serializer/command cases still pass; the C++ commit is unchanged and no DLL was deployed. The description now reflects the successful full build.