Fix: Add position sync for villagers and duplicate check

- Add position property to AddVillagerPacket
- Teleport villager to correct position on client
- Add duplicate guid check to prevent double villager creation
- Send position from Main.cs hook

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

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

Main.cs

@@ -780,6 +780,7 @@ namespace KCM
                         new AddVillagerPacket()
                         {
                             guid = __result.guid,
+                            position = pos,  // Include villager spawn position
                         }.Send();
                     }
                     catch (Exception e)