Anticheat-Lifecycle-Safety

[qutaibakh]

This PR hardens the EasyAntiCheat/EOS plugin lifecycle to reduce stale callback and duplicate session races seen in long-game crashes.

Changes:

• Make BeginSession / EndSession idempotent.
• Track sessionActive, loginInFlight, eventsHooked, and shuttingDown.
• Add session generation IDs and ignore stale callbacks from older sessions.
• Clear host callback pointers through ClearHostCallbacks().
• Unregister EAC notifications before ending sessions or releasing EOS state.
• Avoid EOS/EAC cleanup work in DllMain.
• Add defensive null/state checks.
• Add logs for callback thread ID, generation, peer ID, and shutdown/session state.