合并 main 分支并融合订单列表最小化与 SQL 治理

- Auth/权限中间件取 main 演进版（错误细分、token 来源），保留 dev 的用户 cookie 与登出撤销语义
- 后台订单列表：融合 main 的首页免 COUNT 优化与关键词索引路由，保留 dev 的最小化 AdminOrderListItemDTO（结账明细仍由详情接口返回，同步调整对应集成测试）
- 保留 dev 的 token_version 冻结/解冻递增与 main 的状态变化判断及通知
- 前端：保留 dev 登出接口与 main 的 fetchMe silent 参数、SSE 登录跳转；后台订单表按 dev 最小化 DTO 移除号主到手列

backend/internal/modules/payment/repository_integration_test.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -694,6 +696,75 @@ func TestConfirmPaidRollsBackOrderWhenPaymentUpdateFails(t *testing.T) {
 	}
 }
 
+func TestConcurrentPaidNotificationsAreIdempotent(t *testing.T) {
+	db := database.NewTestDBWithName("payment-concurrent")
+	if err := database.MigrateRentalTransactionTestSchema(db); err != nil {
+		t.Fatalf("数据库迁移失败: %v", err)
+	}
+	sqlDB, err := db.DB()
+	if err != nil {
+		t.Fatalf("get sqlite db: %v", err)
+	}
+	sqlDB.SetMaxOpenConns(8)
+	orderRepo := ordermodule.NewRepository(db)
+	repo := NewRepository(db, nil, orderRepo)
+	fixture := createPayableOrderFixture(t, db, "CONCURRENT", true)
+	params := map[string]string{
+		"third_order_id":    fixture.Payment.ThirdOrderID,
+		"status":            "paid",
+		"amount":            "1000",
+		"provider_order_id": "PROVIDER-CONCURRENT",
+	}
+
+	const callers = 8
+	results := make(chan error, callers)
+	var group sync.WaitGroup
+	for i := 0; i < callers; i++ {
+		group.Add(1)
+		go func() {
+			defer group.Done()
+			var callErr error
+			for attempt := 0; attempt < 50; attempt++ {
+				_, callErr = repo.HandleNotify(t.Context(), "mock", params, "status=paid", "application/x-www-form-urlencoded", "")
+				if callErr == nil || !strings.Contains(callErr.Error(), "locked") {
+					break
+				}
+				time.Sleep(5 * time.Millisecond)
+			}
+			results <- callErr
+		}()
+	}
+	group.Wait()
+	close(results)
+	for callErr := range results {
+		if callErr != nil {
+			t.Fatalf("concurrent HandleNotify() error = %v", callErr)
+		}
+	}
+
+	var latestPayment model.PaymentOrder
+	if err := db.First(&latestPayment, fixture.Payment.ID).Error; err != nil {
+		t.Fatalf("find payment: %v", err)
+	}
+	if latestPayment.Status != "paid" {
+		t.Fatalf("payment status = %q, want paid", latestPayment.Status)
+	}
+	var latestOrder model.RentalOrder
+	if err := db.First(&latestOrder, fixture.Order.ID).Error; err != nil {
+		t.Fatalf("find order: %v", err)
+	}
+	if latestOrder.Status != "pending_handoff" || latestOrder.HandoffStatus != "pending_owner" {
+		t.Fatalf("order status = %q/%q, want pending_handoff/pending_owner", latestOrder.Status, latestOrder.HandoffStatus)
+	}
+	var paidCount int64
+	if err := db.Model(&model.PaymentOrder{}).Where("id = ? AND status = 'paid'", fixture.Payment.ID).Count(&paidCount).Error; err != nil {
+		t.Fatalf("count paid payment: %v", err)
+	}
+	if paidCount != 1 {
+		t.Fatalf("paid payment rows = %d, want 1", paidCount)
+	}
+}
+
 // TestQueryClosedPaymentReturnsLocalStatus 验证关闭状态不再依赖渠道配置或继续轮询渠道。
 func TestQueryClosedPaymentReturnsLocalStatus(t *testing.T) {
 	db := setupPaymentTestDB(t)