feat(web): 通知模板通道多选加公众号选项 (W3)

- 推送通道多选新增 公众号(gzh)
- 提示文案：小程序内为内置通道，短信/微信/公众号/电话需接入外部接口后生效

Ultraworked with [Sisyphus](https://github.com/OhMyOpenCode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

cfc-web/src/views/admin/NotificationTemplateManage.vue

@@ -61,8 +61,12 @@
             <el-checkbox label="in_app">小程序内</el-checkbox>
             <el-checkbox label="sms">短信</el-checkbox>
             <el-checkbox label="wechat">微信</el-checkbox>
+            <el-checkbox label="gzh">公众号</el-checkbox>
             <el-checkbox label="phone">电话</el-checkbox>
           </el-checkbox-group>
+          <div style="color: #999; font-size: 12px; line-height: 1.6">
+            可多选；小程序内为内置通道，短信/微信/公众号/电话需接入外部接口后生效
+          </div>
         </el-form-item>
         <el-form-item label="状态">
           <el-switch v-model="form.status" :active-value="1" :inactive-value="0"></el-switch>
@@ -88,6 +92,7 @@ const CHANNEL_MAP = {
   in_app: { label: '小程序内', type: 'primary' },
   sms: { label: '短信', type: 'warning' },
   wechat: { label: '微信', type: 'success' },
+  gzh: { label: '公众号', type: 'info' },
   phone: { label: '电话', type: 'danger' }
 }