feat(runtime): track upstream response headers in logging and usage reporting

- Added APIs to store, retrieve, and clone upstream response headers in context for detailed logging.
- Updated `RecordAPIResponseMetadata`, `RecordAPIWebsocketHandshake`, and related methods to capture response headers.
- Extended `UsageReporter` to include response headers in published usage records.
- Enhanced payload tests to validate response headers' integrity and persistence.
- Refactored `usage.Record` to support optional `ResponseHeaders` field.

internal/runtime/executor/helps/logging_helpers.go

@@ -102,6 +102,7 @@ func RecordAPIRequest(ctx context.Context, cfg *config.Config, info UpstreamRequ
 
 // RecordAPIResponseMetadata captures upstream response status/header information for the latest attempt.
 func RecordAPIResponseMetadata(ctx context.Context, cfg *config.Config, status int, headers http.Header) {
+	logging.SetResponseHeaders(ctx, headers)
 	if cfg == nil || !cfg.RequestLog {
 		return
 	}
@@ -227,6 +228,7 @@ func RecordAPIWebsocketRequest(ctx context.Context, cfg *config.Config, info Ups
 
 // RecordAPIWebsocketHandshake stores the upstream websocket handshake response metadata.
 func RecordAPIWebsocketHandshake(ctx context.Context, cfg *config.Config, status int, headers http.Header) {
+	logging.SetResponseHeaders(ctx, headers)
 	if cfg == nil || !cfg.RequestLog {
 		return
 	}
@@ -250,6 +252,7 @@ func RecordAPIWebsocketHandshake(ctx context.Context, cfg *config.Config, status
 
 // RecordAPIWebsocketUpgradeRejection stores a rejected websocket upgrade as an HTTP attempt.
 func RecordAPIWebsocketUpgradeRejection(ctx context.Context, cfg *config.Config, info UpstreamRequestLog, status int, headers http.Header, body []byte) {
+	logging.SetResponseHeaders(ctx, headers)
 	if cfg == nil || !cfg.RequestLog {
 		return
 	}

internal/runtime/executor/helps/logging_helpers_test.go

@@ -0,0 +1,24 @@
+package helps
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/logging"
+)
+
+func TestRecordAPIResponseMetadataStoresHeadersWhenRequestLogDisabled(t *testing.T) {
+	ctx := logging.WithResponseHeadersHolder(context.Background())
+	headers := http.Header{}
+	headers.Add("X-Upstream-Request-Id", "upstream-req-1")
+
+	RecordAPIResponseMetadata(ctx, &config.Config{}, http.StatusOK, headers)
+	headers.Set("X-Upstream-Request-Id", "mutated")
+
+	got := logging.GetResponseHeaders(ctx)
+	if got.Get("X-Upstream-Request-Id") != "upstream-req-1" {
+		t.Fatalf("response header = %q, want %q", got.Get("X-Upstream-Request-Id"), "upstream-req-1")
+	}
+}

internal/runtime/executor/helps/usage_helpers.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/gin-gonic/gin"
+	internallogging "github.com/router-for-me/CLIProxyAPI/v7/internal/logging"
 	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/auth"
 	"github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/usage"
 	"github.com/tidwall/gjson"
@@ -60,7 +61,7 @@ func (r *UsageReporter) PublishAdditionalModel(ctx context.Context, model string
 	if !ok {
 		return
 	}
-	usage.PublishRecord(ctx, record)
+	r.publishRecord(ctx, record)
 }
 
 func (r *UsageReporter) buildAdditionalModelRecord(model string, detail usage.Detail) (usage.Record, bool) {
@@ -97,7 +98,7 @@ func (r *UsageReporter) publishWithOutcome(ctx context.Context, detail usage.Det
 	}
 	detail = normalizeUsageDetailTotal(detail)
 	r.once.Do(func() {
-		usage.PublishRecord(ctx, r.buildRecord(detail, failed, fail))
+		r.publishRecord(ctx, r.buildRecord(detail, failed, fail))
 	})
 }
 
@@ -130,10 +131,15 @@ func (r *UsageReporter) EnsurePublished(ctx context.Context) {
 		return
 	}
 	r.once.Do(func() {
-		usage.PublishRecord(ctx, r.buildRecord(usage.Detail{}, false, usage.Failure{}))
+		r.publishRecord(ctx, r.buildRecord(usage.Detail{}, false, usage.Failure{}))
 	})
 }
 
+func (r *UsageReporter) publishRecord(ctx context.Context, record usage.Record) {
+	record.ResponseHeaders = internallogging.GetResponseHeaders(ctx)
+	usage.PublishRecord(ctx, record)
+}
+
 func (r *UsageReporter) buildRecord(detail usage.Detail, failed bool, failures ...usage.Failure) usage.Record {
 	var fail usage.Failure
 	if len(failures) > 0 {