update request log middleware

backend/app/Middleware/RequestLogMiddleware.php

@@ -53,8 +53,8 @@ class RequestLogMiddleware implements MiddlewareInterface
 
         $response_code = self::extractResponseCode($response);
 
-        // 异步协程写库，不阻塞响应返回
-        Coroutine::create(static function () use (
+        // defer 写库：在当前协程退出时执行，响应已返回客户端，同时保证协程内 DB 连接可用
+        Coroutine::defer(static function () use (
             $user_id, $method, $path, $status_code, $ip,
             $user_agent, $request_body, $response_code, $duration_ms
         ): void {
@@ -110,7 +110,12 @@ class RequestLogMiddleware implements MiddlewareInterface
         }
 
         try {
-            $body = (string) $response->getBody();
+            $stream = $response->getBody();
+            $body = (string) $stream;
+            // 回退流指针，避免后续读取得到空内容
+            if ($stream->isSeekable()) {
+                $stream->rewind();
+            }
             $data = json_decode($body, true);
             if (is_array($data) && isset($data['code'])) {
                 return (int) $data['code'];