✨ feat(menu): update word merge function icon

- replace FileMerge icon with GitMerge icon in admin menu
- remove unused FileMerge import in WordMerge page

src/client/admin/menu.tsx

@@ -14,7 +14,8 @@ import {
   Wallet,
   LayoutTemplate,
   UserPlus,
-  FileMerge
+  FileMerge,
+  GitMerge
 } from 'lucide-react';
 
 export interface MenuItem {
@@ -152,7 +153,7 @@ export const useMenu = () => {
     {
       key: 'word-merge',
       label: 'Word合并',
-      icon: <FileMerge className="h-4 w-4" />,
+      icon: <GitMerge className="h-4 w-4" />,
       path: '/admin/word-merge',
       permission: 'file:manage'
     },

src/client/admin/pages/WordMerge.tsx

@@ -2,7 +2,7 @@ import React, { useState, useRef } from 'react';
 import { Button } from '@/client/components/ui/button';
 import { Card, CardContent, CardHeader, CardTitle } from '@/client/components/ui/card';
 import { toast } from 'sonner';
-import { FileMerge, Upload, Download, Trash2, FileText } from 'lucide-react';
+import { Upload, Download, Trash2, FileText } from 'lucide-react';
 
 interface WordFile {
   id: string;