fix: 修复TicketCreatePage浏览按钮缺少<button>标签+补Sparkles import

frontend/src/pages/TicketCreatePage.tsx

@@ -2,7 +2,7 @@ import { useState, useEffect, useCallback, useMemo, useRef } from 'react';
 import { useNavigate } from 'react-router-dom';
 import {
   ChevronRight, Check, AlertTriangle, Shield, Database,
-  Loader2, Clock,
+  Loader2, Clock, Sparkles,
 } from 'lucide-react';
 import { ticketApi } from '@/api/ticket';
 import { instanceApi } from '@/api/instance';
@@ -320,8 +320,10 @@ export default function TicketCreatePage() {
           <div className="flex-1" />
 
           {/* 浏览面板 */}
-          {instanceId && database && (
+          {instanceId && (
+            <button onClick={() => setShowBrowser(!showBrowser)}
               className={`flex items-center gap-1 px-2.5 py-1.5 text-xs font-medium rounded-lg border transition-all ${
+                showBrowser ? 'bg-blue-500/15 text-blue-400 border-blue-500/30' : 'text-[var(--dg-text-secondary)] bg-[var(--dg-bg-tertiary)] border-[var(--dg-border)] hover:bg-[var(--dg-bg-hover)]'
               }`}>
               <Database className="w-3.5 h-3.5" />
               {showBrowser ? '隐藏浏览' : '库表浏览'}