Fix: Add periodic villager position sync from server

- Server syncs villager positions every ~3 seconds to clients
- Only syncs villagers that moved more than 0.5 units (bandwidth optimization)
- Maintains position cache to detect movement
- Clears cache on lobby leave to prevent stale data

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

RiptideSteamTransport/LobbyManager.cs

@@ -160,6 +160,7 @@ namespace Riptide.Demos.Steam.PlayerHosted
             Main.helper.Log("clear players");
             Main.kCPlayers.Clear();
             Main.clientSteamIds.Clear();  // Clear client-to-steam ID mapping
+            Main.ClearVillagerPositionCache();  // Clear villager sync cache
             LobbyHandler.ClearPlayerList();
             LobbyHandler.ClearChatEntries();
             Main.helper.Log("end clear players");