feat(ops): propagate endpoint/request-type context in handlers; add UpstreamURL to upstream error events

backend/internal/handler/gateway_handler.go

@@ -178,6 +178,7 @@ func (h *GatewayHandler) Messages(c *gin.Context) {
 	c.Request = c.Request.WithContext(service.WithThinkingEnabled(c.Request.Context(), parsedReq.ThinkingEnabled, h.metadataBridgeEnabled()))
 
 	setOpsRequestContext(c, reqModel, reqStream, body)
+	setOpsEndpointContext(c, "", int16(service.RequestTypeFromLegacy(reqStream, false)))
 
 	// 验证 model 必填
 	if reqModel == "" {
@@ -1396,6 +1397,7 @@ func (h *GatewayHandler) CountTokens(c *gin.Context) {
 	}
 
 	setOpsRequestContext(c, parsedReq.Model, parsedReq.Stream, body)
+	setOpsEndpointContext(c, "", int16(service.RequestTypeFromLegacy(parsedReq.Stream, false)))
 
 	// 获取订阅信息（可能为nil）
 	subscription, _ := middleware2.GetSubscriptionFromContext(c)