fix(categories): align taxonomy moderation

src/routes/_authed/categories/index.tsx

@@ -141,7 +141,7 @@ function TreeNode({
         {!node.is_active && <Badge variant="secondary">未启用</Badge>}
         {node.approval_status === 'pending' && <Badge variant="outline">待审核</Badge>}
         <span className="ml-auto hidden items-center gap-1 group-hover:flex">
-          {canCreate && (
+          {canCreate && node.level < 3 && (
             <Button variant="ghost" size="icon-sm" onClick={() => onCreateChild(node)} aria-label="新建子分类">
               <Plus className="size-4" />
             </Button>

src/routes/_authed/categories/pending.tsx

@@ -154,7 +154,15 @@ function MergeDialog({
     enabled: source !== null,
   })
 
-  const options = flattenTree(tree.data?.data ?? []).filter((c) => c.id !== source?.id)
+  const options = flattenTree(tree.data?.data ?? []).filter(
+    (category) =>
+      category.id !== source?.id &&
+      category.level === source?.level &&
+      category.parent_id === source?.parent_id &&
+      category.is_active &&
+      category.visibility === 'public' &&
+      category.approval_status === 'approved',
+  )
 
   const submit = async () => {
     if (!source || !targetId) return