feat(api): implement protocol multiplexer and Redis queue for usage integration

- Added `protocol_multiplexer.go`, enabling support for both HTTP and Redis protocols on a single listener.
- Introduced `redis_queue_protocol.go` to handle Redis-compatible RESP commands for queue management.
- Integrated `redisqueue` package, supporting in-memory queuing with expiration pruning.
- Updated server initialization to manage a shared listener and multiplex connections.
- Adjusted `Handler` to adopt `AuthenticateManagementKey` for modular key validation, supporting both HTTP and Redis flows.

internal/redisqueue/plugin_test.go

@@ -0,0 +1,160 @@
+package redisqueue
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	internallogging "github.com/router-for-me/CLIProxyAPI/v6/internal/logging"
+	internalusage "github.com/router-for-me/CLIProxyAPI/v6/internal/usage"
+	coreusage "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/usage"
+)
+
+func TestUsageQueuePluginPayloadIncludesStableFieldsAndSuccess(t *testing.T) {
+	withEnabledQueue(t, func() {
+		ginCtx := newTestGinContext(t, http.MethodPost, "/v1/chat/completions", http.StatusOK)
+		internallogging.SetGinRequestID(ginCtx, "gin-request-id-ignored")
+		ctx := context.WithValue(internallogging.WithRequestID(context.Background(), "ctx-request-id"), "gin", ginCtx)
+
+		plugin := &usageQueuePlugin{}
+		plugin.HandleUsage(ctx, coreusage.Record{
+			Provider:    "openai",
+			Model:       "gpt-5.4",
+			APIKey:      "test-key",
+			AuthIndex:   "0",
+			AuthType:    "apikey",
+			Source:      "user@example.com",
+			RequestedAt: time.Date(2026, 4, 25, 0, 0, 0, 0, time.UTC),
+			Latency:     1500 * time.Millisecond,
+			Detail: coreusage.Detail{
+				InputTokens:  10,
+				OutputTokens: 20,
+				TotalTokens:  30,
+			},
+		})
+
+		payload := popSinglePayload(t)
+		requireStringField(t, payload, "provider", "openai")
+		requireStringField(t, payload, "model", "gpt-5.4")
+		requireStringField(t, payload, "endpoint", "POST /v1/chat/completions")
+		requireStringField(t, payload, "auth_type", "apikey")
+		requireStringField(t, payload, "request_id", "ctx-request-id")
+		requireBoolField(t, payload, "failed", false)
+	})
+}
+
+func TestUsageQueuePluginPayloadIncludesStableFieldsAndFailureAndGinRequestID(t *testing.T) {
+	withEnabledQueue(t, func() {
+		ginCtx := newTestGinContext(t, http.MethodGet, "/v1/responses", http.StatusInternalServerError)
+		internallogging.SetGinRequestID(ginCtx, "gin-request-id")
+		ctx := context.WithValue(context.Background(), "gin", ginCtx)
+
+		plugin := &usageQueuePlugin{}
+		plugin.HandleUsage(ctx, coreusage.Record{
+			Provider:    "openai",
+			Model:       "gpt-5.4-mini",
+			APIKey:      "test-key",
+			AuthIndex:   "0",
+			AuthType:    "apikey",
+			Source:      "user@example.com",
+			RequestedAt: time.Date(2026, 4, 25, 0, 0, 0, 0, time.UTC),
+			Latency:     2500 * time.Millisecond,
+			Detail: coreusage.Detail{
+				InputTokens:  10,
+				OutputTokens: 20,
+				TotalTokens:  30,
+			},
+		})
+
+		payload := popSinglePayload(t)
+		requireStringField(t, payload, "provider", "openai")
+		requireStringField(t, payload, "model", "gpt-5.4-mini")
+		requireStringField(t, payload, "endpoint", "GET /v1/responses")
+		requireStringField(t, payload, "auth_type", "apikey")
+		requireStringField(t, payload, "request_id", "gin-request-id")
+		requireBoolField(t, payload, "failed", true)
+	})
+}
+
+func withEnabledQueue(t *testing.T, fn func()) {
+	t.Helper()
+
+	prevQueueEnabled := Enabled()
+	prevStatsEnabled := internalusage.StatisticsEnabled()
+
+	SetEnabled(false)
+	SetEnabled(true)
+	internalusage.SetStatisticsEnabled(true)
+
+	defer func() {
+		SetEnabled(false)
+		SetEnabled(prevQueueEnabled)
+		internalusage.SetStatisticsEnabled(prevStatsEnabled)
+	}()
+
+	fn()
+}
+
+func newTestGinContext(t *testing.T, method, path string, status int) *gin.Context {
+	t.Helper()
+
+	gin.SetMode(gin.TestMode)
+	recorder := httptest.NewRecorder()
+	ginCtx, _ := gin.CreateTestContext(recorder)
+	ginCtx.Request = httptest.NewRequest(method, "http://example.com"+path, nil)
+	if status != 0 {
+		ginCtx.Status(status)
+	}
+	return ginCtx
+}
+
+func popSinglePayload(t *testing.T) map[string]json.RawMessage {
+	t.Helper()
+
+	items := PopOldest(10)
+	if len(items) != 1 {
+		t.Fatalf("PopOldest() items = %d, want 1", len(items))
+	}
+
+	var payload map[string]json.RawMessage
+	if err := json.Unmarshal(items[0], &payload); err != nil {
+		t.Fatalf("unmarshal payload: %v", err)
+	}
+	return payload
+}
+
+func requireStringField(t *testing.T, payload map[string]json.RawMessage, key, want string) {
+	t.Helper()
+
+	raw, ok := payload[key]
+	if !ok {
+		t.Fatalf("payload missing %q", key)
+	}
+	var got string
+	if err := json.Unmarshal(raw, &got); err != nil {
+		t.Fatalf("unmarshal %q: %v", key, err)
+	}
+	if got != want {
+		t.Fatalf("%s = %q, want %q", key, got, want)
+	}
+}
+
+func requireBoolField(t *testing.T, payload map[string]json.RawMessage, key string, want bool) {
+	t.Helper()
+
+	raw, ok := payload[key]
+	if !ok {
+		t.Fatalf("payload missing %q", key)
+	}
+	var got bool
+	if err := json.Unmarshal(raw, &got); err != nil {
+		t.Fatalf("unmarshal %q: %v", key, err)
+	}
+	if got != want {
+		t.Fatalf("%s = %t, want %t", key, got, want)
+	}
+}