fix(xingbang): 重试范围扩展到瞬时网络错误(502/连接中断/chunked read)

公司网关除 503 外还会抛 502 Bad Gateway / peer closed connection /
incomplete chunked read 等瞬时错误。将所有这些纳入重试, 提升流水线对
不稳定网关的通过率。

backend/xingbang/agents.py

@@ -126,13 +126,18 @@ class XingbangAgent:
             except Exception as e:  # noqa
                 last_err = e
                 msg = str(e)
-                # 仅对 503/限流 重试
-                if "503" in msg or "overloaded" in msg or "429" in msg:
-                    if attempt < max_retries - 1:
-                        await asyncio.sleep(backoff * (2 ** attempt))
-                        continue
+                # 对瞬时网络/网关错误重试: 503过载/502坏网关/429限流/连接中断/不完整响应
+                retriable = any(k in msg for k in (
+                    "503", "502", "overloaded", "429", "rate",
+                    "peer closed", "incomplete chunked", "Bad Gateway",
+                    "timeout", "timed out", "Connection", "connection",
+                    "ReadTimeout", "EOF",
+                ))
+                if retriable and attempt < max_retries - 1:
+                    await asyncio.sleep(backoff * (2 ** attempt))
+                    continue
                 else:
-                    raise  # 非限流错误立即失败
+                    raise  # 非瞬时错误, 或重试耗尽
         else:
             raise RuntimeError(f"网关过载重试后仍失败: {last_err}")
         # 保存产出到文件