fix(gateway): 记录国产厂商原生 Anthropic 直通路径的 reasoning_effort

kimi/zhipu/deepseek 平台分组的 /v1/messages 请求在账号 api_protocol=anthropic
时走零转换直通路径（forwardAnthropicViaNativeAnthropicEndpoint）。该路径的
两个结果构造函数（非流式/流式）从不设置 ReasoningEffort，导致客户端显式
携带 output_config.effort 或启用 thinking 时，usage_log.reasoning_effort
仍恒为 NULL，用量页推理强度列长期显示 '-'。

修复：转发前从入站 body 提取推理强度——优先 Claude 协议 output_config.effort
（NormalizeClaudeOutputEffort），缺失且 thinking 已启用时经
ApplyThinkingEnabledFallback 按 passback-required 白名单兜底为 high，与
Anthropic 网关（gateway_handler）的记录语义对齐；两个结果构造函数补上
ReasoningEffort 字段透传。

测试：新增 4 个单元测试覆盖显式 effort（非流式/流式）、thinking 兜底、
无字段保持 nil 的守卫场景。

backend/internal/service/openai_gateway_messages_anthropic_native.go

@@ -58,6 +58,15 @@ func (s *OpenAIGatewayService) forwardAnthropicViaNativeAnthropicEndpoint(
 		body = rewritten
 	}
 
+	// 记录客户端请求的推理强度：优先 Claude 协议的 output_config.effort；
+	// 缺失且 thinking 已启用时，按国产 passback-required 模型兜底为 high
+	// （对齐 Anthropic 网关 gateway_handler 的记录语义，避免该路径长期落 NULL）。
+	reasoningEffort := ApplyThinkingEnabledFallback(
+		NormalizeClaudeOutputEffort(gjson.GetBytes(body, "output_config.effort").String()),
+		body,
+		billingModel,
+	)
+
 	// 与 Anthropic 平台 passthrough 相同的 pre-filter：剥离空文本块与上游
 	// 无法接受的 web-search 历史块（GLM/Kimi/DeepSeek 对 server_tool_use 400）。
 	body = StripEmptyTextBlocks(body)
@@ -104,9 +113,9 @@ func (s *OpenAIGatewayService) forwardAnthropicViaNativeAnthropicEndpoint(
 	}
 
 	if clientStream {
-		return s.handleNativeAnthropicStreamingResponse(ctx, resp, c, account, originalModel, billingModel, upstreamModel, startTime)
+		return s.handleNativeAnthropicStreamingResponse(ctx, resp, c, account, originalModel, billingModel, upstreamModel, reasoningEffort, startTime)
 	}
-	return s.handleNativeAnthropicBufferedResponse(ctx, resp, c, account, originalModel, billingModel, upstreamModel, startTime)
+	return s.handleNativeAnthropicBufferedResponse(ctx, resp, c, account, originalModel, billingModel, upstreamModel, reasoningEffort, startTime)
 }
 
 // nativeAnthropicTargetURL 组装国产供应商原生 Anthropic messages 端点。
@@ -194,6 +203,7 @@ func (s *OpenAIGatewayService) handleNativeAnthropicBufferedResponse(
 	originalModel string,
 	billingModel string,
 	upstreamModel string,
+	reasoningEffort *string,
 	startTime time.Time,
 ) (*OpenAIForwardResult, error) {
 	if s.rateLimitService != nil {
@@ -239,6 +249,7 @@ func (s *OpenAIGatewayService) handleNativeAnthropicBufferedResponse(
 		UpstreamModel:    upstreamModel,
 		UpstreamEndpoint: "/v1/messages",
 		Stream:           false,
+		ReasoningEffort:  reasoningEffort,
 		Duration:         time.Since(startTime),
 	}, nil
 }
@@ -254,6 +265,7 @@ func (s *OpenAIGatewayService) handleNativeAnthropicStreamingResponse(
 	originalModel string,
 	billingModel string,
 	upstreamModel string,
+	reasoningEffort *string,
 	startTime time.Time,
 ) (*OpenAIForwardResult, error) {
 	observer := upstreamResponseModelObserverFromContext(c)
@@ -382,28 +394,28 @@ func (s *OpenAIGatewayService) handleNativeAnthropicStreamingResponse(
 					flusher.Flush()
 				}
 				if !sawTerminalEvent {
-					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime),
+					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime),
 						fmt.Errorf("stream usage incomplete: missing terminal event")
 				}
-				return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime), nil
+				return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime), nil
 			}
 			if ev.err != nil {
 				if sawTerminalEvent {
-					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime), nil
+					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime), nil
 				}
 				if clientDisconnected {
-					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime),
+					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime),
 						fmt.Errorf("stream usage incomplete after disconnect: %w", ev.err)
 				}
 				if errors.Is(ev.err, context.Canceled) || errors.Is(ev.err, context.DeadlineExceeded) {
-					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime),
+					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime),
 						fmt.Errorf("stream usage incomplete: %w", ev.err)
 				}
 				if errors.Is(ev.err, bufio.ErrTooLong) {
 					logger.LegacyPrintf("service.gateway", "[CN Anthropic 直通] SSE line too long: account=%d max_size=%d error=%v", account.ID, maxLineSize, ev.err)
-					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime), ev.err
+					return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime), ev.err
 				}
-				return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime),
+				return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime),
 					fmt.Errorf("stream read error: %w", ev.err)
 			}
 
@@ -451,14 +463,14 @@ func (s *OpenAIGatewayService) handleNativeAnthropicStreamingResponse(
 				continue
 			}
 			if clientDisconnected {
-				return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime),
+				return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime),
 					fmt.Errorf("stream usage incomplete after timeout")
 			}
 			logger.LegacyPrintf("service.gateway", "[CN Anthropic 直通] Stream data interval timeout: account=%d model=%s interval=%s", account.ID, upstreamModel, streamInterval)
 			if s.rateLimitService != nil {
 				s.rateLimitService.HandleStreamTimeout(ctx, account, upstreamModel)
 			}
-			return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, startTime),
+			return s.nativeAnthropicStreamResult(c, resp, usage, firstTokenMs, clientDisconnected, originalModel, billingModel, upstreamModel, reasoningEffort, startTime),
 				fmt.Errorf("stream data interval timeout")
 
 		case <-keepaliveCh:
@@ -496,6 +508,7 @@ func (s *OpenAIGatewayService) nativeAnthropicStreamResult(
 	originalModel string,
 	billingModel string,
 	upstreamModel string,
+	reasoningEffort *string,
 	startTime time.Time,
 ) *OpenAIForwardResult {
 	if usage == nil {
@@ -509,6 +522,7 @@ func (s *OpenAIGatewayService) nativeAnthropicStreamResult(
 		UpstreamModel:    upstreamModel,
 		UpstreamEndpoint: "/v1/messages",
 		Stream:           true,
+		ReasoningEffort:  reasoningEffort,
 		Duration:         time.Since(startTime),
 		FirstTokenMs:     firstTokenMs,
 		ClientDisconnect: clientDisconnect,

backend/internal/service/openai_gateway_messages_anthropic_native_test.go

@@ -0,0 +1,139 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+)
+
+// 国产供应商原生 Anthropic 直通路径（api_protocol=anthropic）的 reasoning_effort 记录。
+// 回归背景：该路径此前从不提取 Claude 协议的 output_config.effort，也不做
+// thinking-enabled 兜底，导致 kimi/zhipu/deepseek 平台分组的 /v1/messages 请求
+// usage_log.reasoning_effort 恒为 NULL。
+
+func nativeAnthropicTestAccount() *Account {
+	return &Account{
+		ID:          702,
+		Name:        "kimi-native",
+		Platform:    PlatformKimi,
+		Type:        AccountTypeAPIKey,
+		Concurrency: 1,
+		Credentials: map[string]any{
+			"api_key":      "sk-test",
+			"api_protocol": APIProtocolAnthropic,
+			"api_base_urls": map[string]any{
+				APIProtocolAnthropic: "http://anthropic.example",
+			},
+		},
+	}
+}
+
+func nativeAnthropicBufferedResponse() *http.Response {
+	return &http.Response{
+		StatusCode: http.StatusOK,
+		Header:     http.Header{"Content-Type": []string{"application/json"}},
+		Body: io.NopCloser(strings.NewReader(
+			`{"id":"msg_1","type":"message","role":"assistant","model":"k3",` +
+				`"content":[{"type":"text","text":"pong"}],"stop_reason":"end_turn",` +
+				`"usage":{"input_tokens":93,"output_tokens":16}}`,
+		)),
+	}
+}
+
+func nativeAnthropicStreamResponse() *http.Response {
+	sse := `event: message_start
+data: {"type":"message_start","message":{"id":"msg_1","type":"message","role":"assistant","model":"k3","content":[],"stop_reason":null,"usage":{"input_tokens":93,"output_tokens":1}}}
+
+event: content_block_start
+data: {"type":"content_block_start","index":0,"content_block":{"type":"text","text":""}}
+
+event: content_block_delta
+data: {"type":"content_block_delta","index":0,"delta":{"type":"text_delta","text":"pong"}}
+
+event: content_block_stop
+data: {"type":"content_block_stop","index":0}
+
+event: message_delta
+data: {"type":"message_delta","delta":{"stop_reason":"end_turn"},"usage":{"output_tokens":16}}
+
+event: message_stop
+data: {"type":"message_stop"}
+
+`
+	return &http.Response{
+		StatusCode: http.StatusOK,
+		Header:     http.Header{"Content-Type": []string{"text/event-stream"}},
+		Body:       io.NopCloser(strings.NewReader(sse)),
+	}
+}
+
+func TestNativeAnthropicPassthroughRecordsOutputConfigEffort(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	body := []byte(`{"model":"k3","max_tokens":32,"stream":false,` +
+		`"output_config":{"effort":"low"},` +
+		`"messages":[{"role":"user","content":"hi"}]}`)
+	upstream := &httpUpstreamRecorder{resp: nativeAnthropicBufferedResponse()}
+	svc := &OpenAIGatewayService{cfg: rawChatCompletionsTestConfig(), httpUpstream: upstream}
+
+	result, err := svc.ForwardAsAnthropic(context.Background(),
+		adaptiveProtocolTestContext("/v1/messages", body), nativeAnthropicTestAccount(), body, "", "")
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, result.ReasoningEffort)
+	require.Equal(t, "low", *result.ReasoningEffort)
+}
+
+func TestNativeAnthropicPassthroughThinkingEnabledFallback(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	// 未显式传 effort，但 thinking 已启用：k3 属于 passback-required 白名单，应兜底记为 high。
+	body := []byte(`{"model":"k3","max_tokens":32,"stream":false,` +
+		`"thinking":{"type":"enabled","budget_tokens":1024},` +
+		`"messages":[{"role":"user","content":"hi"}]}`)
+	upstream := &httpUpstreamRecorder{resp: nativeAnthropicBufferedResponse()}
+	svc := &OpenAIGatewayService{cfg: rawChatCompletionsTestConfig(), httpUpstream: upstream}
+
+	result, err := svc.ForwardAsAnthropic(context.Background(),
+		adaptiveProtocolTestContext("/v1/messages", body), nativeAnthropicTestAccount(), body, "", "")
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, result.ReasoningEffort)
+	require.Equal(t, "high", *result.ReasoningEffort)
+}
+
+func TestNativeAnthropicPassthroughStreamRecordsEffort(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	body := []byte(`{"model":"k3","max_tokens":32,"stream":true,` +
+		`"output_config":{"effort":"max"},` +
+		`"messages":[{"role":"user","content":"hi"}]}`)
+	upstream := &httpUpstreamRecorder{resp: nativeAnthropicStreamResponse()}
+	svc := &OpenAIGatewayService{cfg: rawChatCompletionsTestConfig(), httpUpstream: upstream}
+
+	result, err := svc.ForwardAsAnthropic(context.Background(),
+		adaptiveProtocolTestContext("/v1/messages", body), nativeAnthropicTestAccount(), body, "", "")
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.NotNil(t, result.ReasoningEffort)
+	require.Equal(t, "max", *result.ReasoningEffort)
+}
+
+func TestNativeAnthropicPassthroughNoEffortStaysNil(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	// 既无 output_config.effort 也未启用 thinking：保持 nil，不做语义注入。
+	body := []byte(`{"model":"k3","max_tokens":32,"stream":false,` +
+		`"messages":[{"role":"user","content":"hi"}]}`)
+	upstream := &httpUpstreamRecorder{resp: nativeAnthropicBufferedResponse()}
+	svc := &OpenAIGatewayService{cfg: rawChatCompletionsTestConfig(), httpUpstream: upstream}
+
+	result, err := svc.ForwardAsAnthropic(context.Background(),
+		adaptiveProtocolTestContext("/v1/messages", body), nativeAnthropicTestAccount(), body, "", "")
+	require.NoError(t, err)
+	require.NotNil(t, result)
+	require.Nil(t, result.ReasoningEffort)
+}