fix(knowledge): 修复知识管理页面统计信息显示错误

- 将第二个统计项从"文件总数"更正为"知识类别"
- 将第三个统计项从"标签总数"更正为"文件总数"
- 在统计数据显示区域调整标签总数的位置
- 确保统计数据与标题正确对应

frontend/src/pages/KnowledgeManagement/Home/KnowledgeManagementPage.tsx

@@ -37,11 +37,11 @@ const DEFAULT_STATISTICS: StatisticsItem[] = [
     value: 0,
   },
   {
-    title: "文件总数",
+    title: "知识类别",
     value: 0,
   },
   {
-    title: "标签总数",
+    title: "文件总数",
     value: 0,
   },
   {
@@ -114,12 +114,12 @@ export default function KnowledgeManagementPage() {
           value: stats?.totalKnowledgeSets ?? 0,
         },
         {
-          title: "文件总数",
+          title: "知识类别",
-          value: stats?.totalFiles ?? 0,
+          value: stats?.totalTags ?? 0,
         },
         {
-          title: "标签总数",
+          title: "文件总数",
-          value: stats?.totalTags ?? 0,
+          value: stats?.totalFiles ?? 0,
         },
         {
           title: "总大小",