更新依赖，优化认证流程；添加聊天框动画效果，优化消息处理逻辑

src/lib/chatStream.ts

@@ -49,14 +49,23 @@ export const streamCopilotChat = async ({
       message,
       conversation_id: conversationId,
     }),
+    skipAuthRedirect: true,
   });
 
   if (!response.ok || !response.body) {
     const detail = await response.text();
+    let message = "stream request failed";
+    
+    if (response.status === 403) {
+      message = "Permission denied. Please contact administrator.";
+    } else if (response.status === 401) {
+      message = "Login expired. Please sign in again.";
+    }
+    
     onEvent({
       type: "error",
-      message: "stream request failed",
-      detail,
+      message,
+      detail: (response.status === 403 || response.status === 401) ? undefined : detail,
     });
     return;
   }