Few small fixes of the mine world.

src/main/java/xyz/soukup/ecoCraftCore/database/objects/Island.java

@@ -109,10 +109,25 @@ public class Island {
         }
     }
 
+    public static Island findByUuid(String uuid) {
+        try {
+            return DaoRegistry.getIslandDao().queryBuilder().where().eq("uuid", uuid).queryForFirst();
+        } catch (SQLException e) {
+            return null;
+        }
+    }
+
 
 
     public void save(){
         try {
+            // createOrUpdate works by primary id; resolve id from uuid first to avoid duplicate inserts.
+            if (this.id <= 0 && this.uuid != null) {
+                Island existing = findByUuid(this.uuid);
+                if (existing != null) {
+                    this.id = existing.id;
+                }
+            }
             DaoRegistry.getIslandDao().createOrUpdate(this);
         } catch (SQLException e) {
             throw new RuntimeException(e);

src/main/java/xyz/soukup/ecoCraftCore/mines/MineWorldManager.java

@@ -107,10 +107,8 @@ public class MineWorldManager implements Listener {
 
         Bukkit.getScheduler().runTaskAsynchronously(plugin, () -> {
             try {
-                if (loader.worldExists(MINE_WORLD_NAME)) {
                 loader.deleteWorld(MINE_WORLD_NAME);
-                    plugin.getLogger().info("[MineWorld] Old mine world deleted.");
+                plugin.getLogger().info("[MineWorld] Old mine world metadata deleted.");
-                }
 
                 SlimePropertyMap properties = new SlimePropertyMap();
                 properties.setValue(SlimeProperties.ENVIRONMENT, "NORMAL");