refactor(network): Remove dynamic allocations for NetPacket

[Caball009]

This PR makes two changes to remove all dynamic allocations for NetPacket:

1. Refactors NetPacket::ConstructBigCommandList so that NetPacket doesn't have to be memory pooled.
2. Removes memory pool for NetPacket, so that it can be stack allocated.

TODO:

• Verify everything works ok.

[greptile-apps]

Greptile Summary

This PR removes all dynamic (pool/heap) allocations for NetPacket by eliminating its MemoryPoolObject base class and replacing ConstructBigCommandPacketList (which returned a list of heap-allocated packets) with ConstructBigCommandList (which returns a single NetCommandList*). Call sites in Connection.cpp and ConnectionManager.cpp now use stack-allocated NetPacket instances.

• ConstructBigCommandList: The new implementation builds chunk refs and adds them directly to a NetCommandList via the addMessage(NetCommandRef*&) overload, which takes ownership — no leak. As a side effect it fixes a relay self-assignment bug in the old code where the inner ref variable shadowed the function parameter, leaving every chunk's relay at its default value of 0.
• sendNetCommandMsg / doSend / doRelay: Stack-allocated NetPacket replaces the static singleton (in sendNetCommandMsg) and per-iteration heap allocations (in doSend and doRelay). MAX_PACKET_SIZE tops out at 1100 bytes so stack usage is well within safe limits.
• Pool entries: Both GameMemoryInitPools_Generals.inl and GameMemoryInitPools_GeneralsMD.inl remove the NetPacket pool row, consistent with the class no longer being pool-managed.

Confidence Score: 5/5

Safe to merge once the author completes their own functional verification (noted in the PR TODO).

The refactoring is mechanically sound. Ownership is correctly transferred to NetCommandList via the addMessage(NetCommandRef*&) overload, ref-counting through wrapperMsg is preserved, and MAX_PACKET_SIZE (≤1100 bytes) keeps stack usage well within normal limits. The change also incidentally fixes the old relay self-assignment bug. No regressions were found in the changed paths.

No files require special attention beyond the author completing their functional test pass.

Important Files Changed

Filename	Overview
Core/GameEngine/Include/GameNetwork/NetPacket.h	Removes MemoryPoolObject base class and pool glue macros; changes constructor to take TransportMessage by const-ref; replaces NetPacketList/ConstructBigCommandPacketList with new ConstructBigCommandList returning NetCommandList*.
Core/GameEngine/Source/GameNetwork/NetPacket.cpp	Rewrites ConstructBigCommandPacketList as ConstructBigCommandList, allocating chunks directly into a NetCommandList. Also fixes a relay self-assignment bug from the old code. Ownership model is correct: addMessage(NetCommandRef*&) takes ownership of each chunkRef.
Core/GameEngine/Source/GameNetwork/Connection.cpp	Replaces heap-allocated NetPacket (static singleton in sendNetCommandMsg and per-iteration allocation in doSend) with stack-allocated instances. Simplifies the big-command path to iterate directly over NetCommandList instead of NetPacketList.
Core/GameEngine/Source/GameNetwork/ConnectionManager.cpp	Switches doRelay to use stack-allocated NetPacket per loop iteration; correctly removes the outer-loop deleteInstance(packet) which was a nullptr no-op in the original.
Core/GameEngine/Source/Common/System/GameMemoryInitPools_Generals.inl	Removes the NetPacket pool entry, consistent with the class no longer deriving from MemoryPoolObject.
Core/GameEngine/Source/Common/System/GameMemoryInitPools_GeneralsMD.inl	Same NetPacket pool entry removal as the Generals variant; symmetric change.

_{Reviews (5): Last reviewed commit: "Removed memory pool for NetPacket." | Re-trigger Greptile}

[xezon]

What is the motivation for removing memory pool? The main purpose of memory pool is cache and defrag friendlyness.

[Caball009]

What is the motivation for removing memory pool? The main purpose of memory pool is cache and defrag friendlyness.

The purpose of a memory pool is to mitigate the downsides of frequent dynamic allocations. It's unnecessary if you don't need dynamic allocations.

[xezon]

But it is still allocated with NetPacket *packet = new(NetPacket);

[Caball009]

But it is still allocated with NetPacket *packet = new(NetPacket);

Rewritten so that this is no longer the case.

[Caball009]

@greptileai re-review this pull request.