fix: 授权按钮添加 overflow/min-width/min-height 保持圆形

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

haha-mp/src/pages/index/index.vue

@@ -366,10 +366,14 @@ const onContactSuccess = () => logger.log('[首页] 客服会话已打开')
 .auth-button {
   width: 400rpx;
   height: 400rpx;
+  min-width: 400rpx;
+  min-height: 400rpx;
   border-radius: 50%;
   background: transparent;
   border: none;
   padding: 0;
+  margin: 0;
+  overflow: hidden;
 
   &::after { border: none; }