fix: 修复api.js中toast调用方式

- uni.$u.toast.loading/hide 改为 uni.showLoading/hideLoading
- uni.$u.toast.error 改为 uni.showToast
- uview-plus的toast API与uview-ui不同

utils/api.js

@@ -17,7 +17,7 @@ let loginLock = null;
 let loadingCount = 0;
 const showLoading = () => {
   if (loadingCount === 0) {
-    uni.$u.toast.loading('加载中...');
+    uni.showLoading({ title: '加载中...', mask: true });
   }
   loadingCount++;
 };
@@ -25,7 +25,7 @@ const hideLoading = () => {
   loadingCount--;
   if (loadingCount <= 0) {
     loadingCount = 0;
-    uni.$u.toast.hide();
+    uni.hideLoading();
   }
 };
 
@@ -196,7 +196,7 @@ const requestWithRetry = async (url, method = 'GET', data = {}, headers = {}, re
         return await requestWithRetry(url, method, data, headers, retryCount + 1);
       } else {
         console.error('❌ 达到最大重试次数');
-        uni.$u.toast.error('系统异常，请稍后重试');
+        uni.showToast({ title: '系统异常，请稍后重试', icon: 'none' });
         throw new Error('登录已过期，重试次数超限');
       }
     } else {