feat: record stream interruption reasons via StreamStatus

- Add StreamStatus type (relay/common) to track stream end reason
  (done/timeout/client_gone/scanner_error/eof/panic/ping_fail) and
  accumulate soft errors during streaming via sync.Once + sync.Mutex.
- Add StreamResult (relay/helper) as the callback interface: adapters
  call sr.Error() for soft errors, sr.Stop() for fatal, sr.Done() for
  normal completion. No early-return problem — multiple errors per chunk
  are naturally supported.
- Refactor StreamScannerHandler callback from func(string) bool to
  func(string, *StreamResult). All 9 channel adapters updated.
- Write stream_status into log other JSON field (admin-only) with
  status ok/error, end_reason, error_count, and error messages.
- Frontend: display stream status in log detail expansion for admins.

relay/helper/stream_scanner.go

@@ -34,12 +34,15 @@ func getScannerBufferSize() int {
 	return DefaultMaxScannerBufferSize
 }
 
-func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo, dataHandler func(data string) bool) {
+func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo, dataHandler func(data string, sr *StreamResult)) {
 
 	if resp == nil || dataHandler == nil {
 		return
 	}
 
+	// 无条件新建 StreamStatus
+	info.StreamStatus = relaycommon.NewStreamStatus()
+
 	// 确保响应体总是被关闭
 	defer func() {
 		if resp.Body != nil {
@@ -121,6 +124,7 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 				wg.Done()
 				if r := recover(); r != nil {
 					logger.LogError(c, fmt.Sprintf("ping goroutine panic: %v", r))
+					info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonPanic, fmt.Errorf("ping panic: %v", r))
 					common.SafeSendBool(stopChan, true)
 				}
 				if common.DebugEnabled {
@@ -148,6 +152,7 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 					case err := <-done:
 						if err != nil {
 							logger.LogError(c, "ping data error: "+err.Error())
+							info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonPingFail, err)
 							return
 						}
 						if common.DebugEnabled {
@@ -155,6 +160,7 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 						}
 					case <-time.After(10 * time.Second):
 						logger.LogError(c, "ping data send timeout")
+						info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonPingFail, fmt.Errorf("ping send timeout"))
 						return
 					case <-ctx.Done():
 						return
@@ -184,14 +190,17 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 			wg.Done()
 			if r := recover(); r != nil {
 				logger.LogError(c, fmt.Sprintf("data handler goroutine panic: %v", r))
+				info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonPanic, fmt.Errorf("handler panic: %v", r))
 			}
 			common.SafeSendBool(stopChan, true)
 		}()
+		sr := newStreamResult(info.StreamStatus)
 		for data := range dataChan {
+			sr.reset()
 			writeMutex.Lock()
-			success := dataHandler(data)
+			dataHandler(data, sr)
 			writeMutex.Unlock()
-			if !success {
+			if sr.IsStopped() {
 				return
 			}
 		}
@@ -205,6 +214,7 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 			wg.Done()
 			if r := recover(); r != nil {
 				logger.LogError(c, fmt.Sprintf("scanner goroutine panic: %v", r))
+				info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonPanic, fmt.Errorf("scanner panic: %v", r))
 			}
 			common.SafeSendBool(stopChan, true)
 			if common.DebugEnabled {
@@ -220,6 +230,7 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 			case <-ctx.Done():
 				return
 			case <-c.Request.Context().Done():
+				info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonClientGone, c.Request.Context().Err())
 				return
 			default:
 			}
@@ -253,7 +264,7 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 					return
 				}
 			} else {
-				// done, 处理完成标志，直接退出停止读取剩余数据防止出错
+				info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonDone, nil)
 				if common.DebugEnabled {
 					println("received [DONE], stopping scanner")
 				}
@@ -264,20 +275,25 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 		if err := scanner.Err(); err != nil {
 			if err != io.EOF {
 				logger.LogError(c, "scanner error: "+err.Error())
+				info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonScannerErr, err)
 			}
 		}
+		info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonEOF, nil)
 	})
 
 	// 主循环等待完成或超时
 	select {
 	case <-ticker.C:
-		// 超时处理逻辑
-		logger.LogError(c, "streaming timeout")
+		info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonTimeout, nil)
 	case <-stopChan:
-		// 正常结束
-		logger.LogInfo(c, "streaming finished")
+		// EndReason already set by the goroutine that triggered stopChan
 	case <-c.Request.Context().Done():
-		// 客户端断开连接
-		logger.LogInfo(c, "client disconnected")
+		info.StreamStatus.SetEndReason(relaycommon.StreamEndReasonClientGone, c.Request.Context().Err())
+	}
+
+	if info.StreamStatus.IsNormalEnd() && !info.StreamStatus.HasErrors() {
+		logger.LogInfo(c, fmt.Sprintf("stream ended: %s", info.StreamStatus.Summary()))
+	} else {
+		logger.LogError(c, fmt.Sprintf("stream ended: %s, received=%d", info.StreamStatus.Summary(), info.ReceivedResponseCount))
 	}
 }