refactor(frontend): replace toast system with zibll notyf

assets/js/follow.js

@@ -40,11 +40,11 @@
             var isFollowing = result.data.is_following;
             updateFollowButton(btn, isFollowing, result.data.follower_count);
           } else {
-            showToast(result.message || '操作失败', 'error');
+            notyf(result.message || '操作失败', 'danger');
           }
         })
         .catch(function () {
-          showToast('网络错误，请重试', 'error');
+          notyf('网络错误，请重试', 'danger');
         })
         .finally(function () {
           btn.disabled = false;
@@ -108,18 +108,6 @@
     }
   }
 
-  function showToast(msg, type) {
-    var toast = document.createElement('div');
-    toast.textContent = msg;
-    toast.style.cssText = 'position:fixed;top:20px;left:50%;transform:translateX(-50%);padding:12px 24px;border-radius:6px;color:#fff;font-size:14px;z-index:10000;transition:opacity 0.3s;';
-    toast.style.background = type === 'error' ? '#e74c3c' : '#27ae60';
-    document.body.appendChild(toast);
-    setTimeout(function () {
-      toast.style.opacity = '0';
-      setTimeout(function () { toast.remove(); }, 300);
-    }, 3000);
-  }
-
   if (document.readyState === 'loading') {
     document.addEventListener('DOMContentLoaded', initFollowButtons);
   } else {