fix: ensure proper destruction of helper instances in hideLinkController

Author: SSShooter

src/arrow.ts

@@ -190,6 +190,8 @@ export const unselectArrow = function (this: MindElixirInstance) {
 }
 
 const hideLinkController = function (mei: MindElixirInstance) {
+  mei.helper1?.destory(mei.map)
+  mei.helper2?.destory(mei.map)
   mei.linkController.style.display = 'none'
   mei.P2.style.display = 'none'
   mei.P3.style.display = 'none'
@@ -224,11 +226,6 @@ const showLinkController = function (mei: MindElixirInstance, linkItem: Arrow, f
     y2: p4y + '',
   })
 
-  if (mei.helper1) {
-    mei.helper1.destory(mei.map)
-    mei.helper2?.destory(mei.map)
-  }
-
   mei.helper1 = LinkDragMoveHelper.create(mei.P2)
   mei.helper2 = LinkDragMoveHelper.create(mei.P3)