fix: title auto-visible when text entered + add show/hide switch

Typing title text now auto-sets visible=true so the title appears
immediately. Also added a Switch to toggle title visibility.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/frameworks/components/configPanel/TitleConfig.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import React, { useCallback } from 'react';
-import { Input, InputNumber, Select, ColorPicker, Space, Typography } from 'antd';
+import { Input, InputNumber, Select, ColorPicker, Switch, Space, Typography } from 'antd';
 import { useChartConfig } from '@/frameworks/hooks/useChartConfig';
 import type { TitleStyle } from '@/domain/entities/StyleConfig';
 
@@ -23,11 +23,19 @@ export default function TitleConfig() {
 
   return (
     <Space direction="vertical" style={{ width: '100%' }} size={12}>
+      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
+        <Text style={{ fontSize: 12 }}>显示标题</Text>
+        <Switch
+          size="small"
+          checked={title.visible}
+          onChange={(checked) => update({ visible: checked })}
+        />
+      </div>
       <div>
         <Text style={{ fontSize: 12 }}>标题文本</Text>
         <Input
           value={title.text}
-          onChange={(e) => update({ text: e.target.value })}
+          onChange={(e) => update({ text: e.target.value, visible: true })}
           placeholder="请输入标题"
           size="small"
           style={{ marginTop: 4 }}