fix(observability): 治理SSE慢请求虚报、客户端取消日志污染、退款重试刷屏与会话计数慢查询

backend/internal/middleware/request_logger.go

@@ -1,6 +1,8 @@
 package middleware
 
 import (
+	"context"
+	"errors"
 	"net/http"
 	"strings"
 	"time"
@@ -72,6 +74,10 @@ func RequestLogger(logger *zap.Logger) gin.HandlerFunc {
 		}
 
 		switch {
+		case errors.Is(c.Request.Context().Err(), context.Canceled):
+			if logger.Core().Enabled(zap.DebugLevel) {
+				logger.Debug("HTTP 客户端中断连接", fields...)
+			}
 		case status >= 500:
 			logger.Error("HTTP 请求失败", fields...)
 		case status == http.StatusTooManyRequests:
@@ -113,7 +119,7 @@ func shouldSkipHTTPLog(path, route string, status int, latencyMs float64) bool {
 		return false
 	}
 	// SSE 的请求耗时就是连接存活时间，由 chathub 单独记录连接生命周期。
-	if isChatSSEPath(path, route) {
+	if isSSEPath(path, route) {
 		return true
 	}
 	if latencyMs >= slowRequestThresholdMs {
@@ -122,9 +128,10 @@ func shouldSkipHTTPLog(path, route string, status int, latencyMs float64) bool {
 	return true
 }
 
-func isChatSSEPath(path, route string) bool {
-	return path == "/api/chats/events" || path == "/api/admin/chats/events" ||
-		route == "/api/chats/events" || route == "/api/admin/chats/events"
+func isSSEPath(path, route string) bool {
+	return path == "/api/auth/events" || route == "/api/auth/events" ||
+		path == "/api/chats/events" || route == "/api/chats/events" ||
+		path == "/api/admin/chats/events" || route == "/api/admin/chats/events"
 }
 
 func meaningfulAuthFailure(c *gin.Context) bool {