feat: enhance AutoRegister annotation and refactor CustomItemManager for improved initialization

Author: Pinont

src/main/java/com/github/pinont/singularitylib/api/annotation/AutoRegister.java

@@ -1,5 +1,8 @@
 package com.github.pinont.singularitylib.api.annotation;
 
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+
 /**
  * Annotation to mark classes for automatic registration by the plugin.
  * This annotation is used to mark classes that need to be registered during the plugin's startup process.
@@ -10,6 +13,7 @@
  * It should only be used when the class extends {@code CustomItem}, {@code SimpleCommand}, or {@code Listener}.
  */
 
+@Target({ElementType.TYPE})
 public @interface AutoRegister {
     /**
      * Indicates that the annotated class should be automatically registered by the plugin.

src/main/java/com/github/pinont/singularitylib/api/manager/CustomItemManager.java

@@ -37,7 +37,7 @@ public class CustomItemManager implements SimpleCommand {
      * Used when the dev tool plugin is present to provide additional
      * development and debugging features for custom items.
      */
-    private final CItemManager customItemManager = new CItemManager();
+    private CItemManager customItemManager;
 
     /**
      * Default constructor for CustomItemManager.
@@ -73,7 +73,7 @@ public List<CustomItem> getCustomItems() {
     public void register(List<CustomItem> item) {
         if (item.isEmpty()) return;
         sendConsoleMessage("Registering " + item.size() + " custom items");
-        if (getInstance().getServer().getPluginManager().getPlugin("SingularityDevTool") != null) {
+        if (Common.plugin != null) {
             registerAllItems(item, true);
         }
         registerAllItems(item);
@@ -104,6 +104,9 @@ private void registerAllItems(List<CustomItem> items) {
      * @param forDevTool whether to register items with the development tool
      */
     private void registerAllItems(List<CustomItem> items, boolean forDevTool) {
+        if (forDevTool) {
+            customItemManager = new CItemManager();
+        }
         for (CustomItem customItem : items) {
             customItems.add(customItem);
             if (forDevTool) {

src/main/java/com/github/pinont/singularitylib/plugin/register/Register.java

@@ -1,6 +1,5 @@
 package com.github.pinont.singularitylib.plugin.register;
 
-import com.github.pinont.devtool.api.CItemManager;
 import com.github.pinont.singularitylib.api.annotation.AutoRegister;
 import com.github.pinont.singularitylib.api.command.SimpleCommand;
 import com.github.pinont.singularitylib.api.items.CustomItem;