Add mount edge case handling for dismount scenarios

- Player logout: Dismount from NPC mount before logout to prevent
  orphaned mount state (ServerTickHandler)
- Teleportation: Dismount before cross-dimension teleport to prevent
  mount being left behind in old dimension (NoppesUtilPlayer)
- Dead rider: Validate rider is alive, dismount dead/invalid riders
  to prevent stuck mount state (NPCMountUtil)
- Role disable: Dismount rider when mount role is disabled to prevent
  mounted player on non-mount NPC (RoleMount)

src/main/java/noppes/npcs/ServerTickHandler.java

@@ -11,6 +11,7 @@ import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.WorldServer;
 import noppes.npcs.client.AnalyticsTracking;
 import noppes.npcs.controllers.data.PlayerData;
+import noppes.npcs.entity.EntityNPCInterface;
 import noppes.npcs.controllers.data.action.ActionManager;
 
 import java.net.InetAddress;
@@ -68,6 +69,11 @@ public class ServerTickHandler {
 
     @SubscribeEvent
     public void playerLogout(PlayerEvent.PlayerLoggedOutEvent event) {
+        // Dismount player from NPC mount before logout to prevent orphaned mount state
+        if (event.player.ridingEntity instanceof EntityNPCInterface) {
+            event.player.mountEntity(null);
+        }
+
         PlayerData playerData = PlayerData.get(event.player);
         if (playerData != null) {
             playerData.onLogout();