[1.8.9] 5zig party bug (chat flow persists across servers)

Submitter: Aktimoose
When the party leader of a party switches servers while the members are still on a server, the chat from the first server will persist for the party members (including new messages, as if they are still on the first server), and they will see chat from both servers simultaneously

Look for party chat handling code, likely in network or chat modules. The bug involves chat persistence across server switches. Start by finding where party messages are routed and stored. Check if chat sessions are properly cleared on server disconnect. Test by simulating a party leader switching servers while others remain.

索引モデルが issue の本文から書いたものです。