feat: add expiry reminder subscription API (POST /subscribe/expiry-save) and send reminders endpoint

src/services/wechatSubscribeService.js

@@ -81,6 +81,21 @@ class WechatSubscribeService {
       data
     });
   }
+  
+  static async sendExpiryReminderMessage({ openid, templateId, thing1, thing2, phrase3 }) {
+    const data = {
+      thing1: { value: thing1 },
+      thing2: { value: thing2 },
+      phrase3: { value: phrase3 }
+    };
+    
+    return this.sendSubscribeMessage({
+      touser: openid,
+      templateId,
+      page: 'pages/profile/profile',
+      data
+    });
+  }
 }
 
 module.exports = WechatSubscribeService;