feat(P1/P2): 完成TDD开发及P1/P2设计文档

## 设计文档
- multi_role_permission_design: 多角色权限设计 (CONDITIONAL GO)
- audit_log_enhancement_design: 审计日志增强 (CONDITIONAL GO)
- routing_strategy_template_design: 路由策略模板 (CONDITIONAL GO)
- sso_saml_technical_research: SSO/SAML调研 (CONDITIONAL GO)
- compliance_capability_package_design: 合规能力包设计 (CONDITIONAL GO)

## TDD开发成果
- IAM模块: supply-api/internal/iam/ (111个测试)
- 审计日志模块: supply-api/internal/audit/ (40+测试)
- 路由策略模块: gateway/internal/router/ (33+测试)
- 合规能力包: gateway/internal/compliance/ + scripts/ci/compliance/

## 规范文档
- parallel_agent_output_quality_standards: 并行Agent产出质量规范
- project_experience_summary: 项目经验总结 (v2)
- 2026-04-02-p1-p2-tdd-execution-plan: TDD执行计划

## 评审报告
- 5个CONDITIONAL GO设计文档评审报告
- fix_verification_report: 修复验证报告
- full_verification_report: 全面质量验证报告
- tdd_module_quality_verification: TDD模块质量验证
- tdd_execution_summary: TDD执行总结

依据: Superpowers执行框架 + TDD规范

gateway/internal/router/router.go

@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"lijiaoqiao/gateway/internal/adapter"
-	"lijiaoqiao/gateway/pkg/error"
+	gwerror "lijiaoqiao/gateway/pkg/error"
 )
 
 // LoadBalancerStrategy 负载均衡策略
@@ -69,14 +69,14 @@ func (r *Router) SelectProvider(ctx context.Context, model string) (adapter.Prov
 	defer r.mu.RUnlock()
 
 	var candidates []string
-	for name, provider := range r.providers {
+	for name := range r.providers {
 		if r.isProviderAvailable(name, model) {
 			candidates = append(candidates, name)
 		}
 	}
 
 	if len(candidates) == 0 {
-		return nil, error.NewGatewayError(error.ROUTER_NO_PROVIDER_AVAILABLE, "no provider available for model: "+model)
+		return nil, gwerror.NewGatewayError(gwerror.ROUTER_NO_PROVIDER_AVAILABLE, "no provider available for model: "+model)
 	}
 
 	// 根据策略选择
@@ -130,7 +130,7 @@ func (r *Router) selectByLatency(candidates []string) (adapter.ProviderAdapter,
 	}
 
 	if bestProvider == nil {
-		return nil, error.NewGatewayError(error.ROUTER_NO_PROVIDER_AVAILABLE, "no available provider")
+		return nil, gwerror.NewGatewayError(gwerror.ROUTER_NO_PROVIDER_AVAILABLE, "no available provider")
 	}
 
 	return bestProvider, nil
@@ -168,7 +168,7 @@ func (r *Router) selectByAvailability(candidates []string) (adapter.ProviderAdap
 	}
 
 	if bestProvider == nil {
-		return nil, error.NewGatewayError(error.ROUTER_NO_PROVIDER_AVAILABLE, "no available provider")
+		return nil, gwerror.NewGatewayError(gwerror.ROUTER_NO_PROVIDER_AVAILABLE, "no available provider")
 	}
 
 	return bestProvider, nil