fix: 验证并修复comprehensive_review_v4问题

已验证的问题状态：
1. P0-07补偿处理器 - 已集成到main.go ✅
2. P0-09外键校验器 - 已集成到main.go并调用 ✅
3. 幂等协议Idempotency-Key - 已在idempotency.go实现 ✅
4. 幂等唯一索引 - 已在SQL中定义 ✅

Gateway修复：
- 修复cors.go语法错误（重复函数定义）
- 修复middleware_test.go参数不匹配问题
- 修复go.mod降级到go 1.21解决依赖问题

gateway/internal/middleware/middleware_test.go

@@ -184,7 +184,7 @@ func TestQueryKeyRejectMiddleware(t *testing.T) {
 
 		handler := queryKeyRejectMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			t.Error("next handler should not be called")
-		}), auditor, time.Now)
+		}), auditor, time.Now, nil)
 
 		req := httptest.NewRequest("GET", "/api/v1/supply?key=abc123", nil)
 		rr := httptest.NewRecorder()
@@ -202,7 +202,7 @@ func TestQueryKeyRejectMiddleware(t *testing.T) {
 		nextCalled := false
 		handler := queryKeyRejectMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			nextCalled = true
-		}), nil, time.Now)
+		}), nil, time.Now, nil)
 
 		req := httptest.NewRequest("GET", "/api/v1/supply?name=test", nil)
 		rr := httptest.NewRecorder()
@@ -216,7 +216,7 @@ func TestQueryKeyRejectMiddleware(t *testing.T) {
 	t.Run("rejects api_key parameter", func(t *testing.T) {
 		handler := queryKeyRejectMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			t.Error("next handler should not be called")
-		}), nil, time.Now)
+		}), nil, time.Now, nil)
 
 		req := httptest.NewRequest("GET", "/api/v1/supply?api_key=secret", nil)
 		rr := httptest.NewRecorder()