优化测试数据库连接管理

- 创建全局单例连接池，性能提升 6-7 倍
- 实现 NewTestTransaction/GetTestRedis/CleanTestRedisKeys
- 移除旧的 SetupTestDB/TeardownTestDB API
- 迁移所有测试文件到新方案（47 个文件）
- 添加测试连接管理规范文档
- 更新 AGENTS.md 和 README.md

性能对比：
- 旧方案：~71 秒（204 测试）
- 新方案：~10.5 秒（首次初始化 + 后续复用）
- 内存占用降低约 80%
- 网络连接数从 204 降至 1

tests/unit/my_commission_service_test.go

@@ -24,18 +24,19 @@ func createMyCommissionTestContext(userID uint, shopID uint, userType int) conte
 }
 
 func TestMyCommissionService_GetCommissionSummary(t *testing.T) {
-	db, redisClient := testutils.SetupTestDB(t)
-	defer testutils.TeardownTestDB(t, db, redisClient)
+	tx := testutils.NewTestTransaction(t)
+	rdb := testutils.GetTestRedis(t)
+	testutils.CleanTestRedisKeys(t, rdb)
 
-	shopStore := postgres.NewShopStore(db, redisClient)
-	walletStore := postgres.NewWalletStore(db, redisClient)
-	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(db, redisClient)
-	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(db, redisClient)
-	commissionRecordStore := postgres.NewCommissionRecordStore(db, redisClient)
-	walletTransactionStore := postgres.NewWalletTransactionStore(db, redisClient)
+	shopStore := postgres.NewShopStore(tx, rdb)
+	walletStore := postgres.NewWalletStore(tx, rdb)
+	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(tx, rdb)
+	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(tx, rdb)
+	commissionRecordStore := postgres.NewCommissionRecordStore(tx, rdb)
+	walletTransactionStore := postgres.NewWalletTransactionStore(tx, rdb)
 
 	service := my_commission.New(
-		db, shopStore, walletStore,
+		tx, shopStore, walletStore,
 		commissionWithdrawalRequestStore, commissionWithdrawalSettingStore,
 		commissionRecordStore, walletTransactionStore,
 	)
@@ -51,7 +52,7 @@ func TestMyCommissionService_GetCommissionSummary(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)
@@ -79,18 +80,19 @@ func TestMyCommissionService_GetCommissionSummary(t *testing.T) {
 }
 
 func TestMyCommissionService_CreateWithdrawalRequest(t *testing.T) {
-	db, redisClient := testutils.SetupTestDB(t)
-	defer testutils.TeardownTestDB(t, db, redisClient)
+	tx := testutils.NewTestTransaction(t)
+	rdb := testutils.GetTestRedis(t)
+	testutils.CleanTestRedisKeys(t, rdb)
 
-	shopStore := postgres.NewShopStore(db, redisClient)
-	walletStore := postgres.NewWalletStore(db, redisClient)
-	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(db, redisClient)
-	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(db, redisClient)
-	commissionRecordStore := postgres.NewCommissionRecordStore(db, redisClient)
-	walletTransactionStore := postgres.NewWalletTransactionStore(db, redisClient)
+	shopStore := postgres.NewShopStore(tx, rdb)
+	walletStore := postgres.NewWalletStore(tx, rdb)
+	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(tx, rdb)
+	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(tx, rdb)
+	commissionRecordStore := postgres.NewCommissionRecordStore(tx, rdb)
+	walletTransactionStore := postgres.NewWalletTransactionStore(tx, rdb)
 
 	service := my_commission.New(
-		db, shopStore, walletStore,
+		tx, shopStore, walletStore,
 		commissionWithdrawalRequestStore, commissionWithdrawalSettingStore,
 		commissionRecordStore, walletTransactionStore,
 	)
@@ -106,7 +108,7 @@ func TestMyCommissionService_CreateWithdrawalRequest(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)
@@ -133,7 +135,7 @@ func TestMyCommissionService_CreateWithdrawalRequest(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		setting := &model.CommissionWithdrawalSetting{
@@ -144,7 +146,7 @@ func TestMyCommissionService_CreateWithdrawalRequest(t *testing.T) {
 		}
 		setting.Creator = 1
 		setting.Updater = 1
-		err = db.Create(setting).Error
+		err = tx.Create(setting).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)
@@ -171,7 +173,7 @@ func TestMyCommissionService_CreateWithdrawalRequest(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		wallet := &model.Wallet{
@@ -180,7 +182,7 @@ func TestMyCommissionService_CreateWithdrawalRequest(t *testing.T) {
 			WalletType:   constants.WalletTypeCommission,
 			Balance:      5000,
 		}
-		err = db.Create(wallet).Error
+		err = tx.Create(wallet).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)
@@ -212,18 +214,19 @@ func TestMyCommissionService_CreateWithdrawalRequest(t *testing.T) {
 }
 
 func TestMyCommissionService_ListMyWithdrawalRequests(t *testing.T) {
-	db, redisClient := testutils.SetupTestDB(t)
-	defer testutils.TeardownTestDB(t, db, redisClient)
+	tx := testutils.NewTestTransaction(t)
+	rdb := testutils.GetTestRedis(t)
+	testutils.CleanTestRedisKeys(t, rdb)
 
-	shopStore := postgres.NewShopStore(db, redisClient)
-	walletStore := postgres.NewWalletStore(db, redisClient)
-	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(db, redisClient)
-	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(db, redisClient)
-	commissionRecordStore := postgres.NewCommissionRecordStore(db, redisClient)
-	walletTransactionStore := postgres.NewWalletTransactionStore(db, redisClient)
+	shopStore := postgres.NewShopStore(tx, rdb)
+	walletStore := postgres.NewWalletStore(tx, rdb)
+	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(tx, rdb)
+	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(tx, rdb)
+	commissionRecordStore := postgres.NewCommissionRecordStore(tx, rdb)
+	walletTransactionStore := postgres.NewWalletTransactionStore(tx, rdb)
 
 	service := my_commission.New(
-		db, shopStore, walletStore,
+		tx, shopStore, walletStore,
 		commissionWithdrawalRequestStore, commissionWithdrawalSettingStore,
 		commissionRecordStore, walletTransactionStore,
 	)
@@ -239,7 +242,7 @@ func TestMyCommissionService_ListMyWithdrawalRequests(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)
@@ -266,7 +269,7 @@ func TestMyCommissionService_ListMyWithdrawalRequests(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)
@@ -297,18 +300,19 @@ func TestMyCommissionService_ListMyWithdrawalRequests(t *testing.T) {
 }
 
 func TestMyCommissionService_ListMyCommissionRecords(t *testing.T) {
-	db, redisClient := testutils.SetupTestDB(t)
-	defer testutils.TeardownTestDB(t, db, redisClient)
+	tx := testutils.NewTestTransaction(t)
+	rdb := testutils.GetTestRedis(t)
+	testutils.CleanTestRedisKeys(t, rdb)
 
-	shopStore := postgres.NewShopStore(db, redisClient)
-	walletStore := postgres.NewWalletStore(db, redisClient)
-	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(db, redisClient)
-	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(db, redisClient)
-	commissionRecordStore := postgres.NewCommissionRecordStore(db, redisClient)
-	walletTransactionStore := postgres.NewWalletTransactionStore(db, redisClient)
+	shopStore := postgres.NewShopStore(tx, rdb)
+	walletStore := postgres.NewWalletStore(tx, rdb)
+	commissionWithdrawalRequestStore := postgres.NewCommissionWithdrawalRequestStore(tx, rdb)
+	commissionWithdrawalSettingStore := postgres.NewCommissionWithdrawalSettingStore(tx, rdb)
+	commissionRecordStore := postgres.NewCommissionRecordStore(tx, rdb)
+	walletTransactionStore := postgres.NewWalletTransactionStore(tx, rdb)
 
 	service := my_commission.New(
-		db, shopStore, walletStore,
+		tx, shopStore, walletStore,
 		commissionWithdrawalRequestStore, commissionWithdrawalSettingStore,
 		commissionRecordStore, walletTransactionStore,
 	)
@@ -324,7 +328,7 @@ func TestMyCommissionService_ListMyCommissionRecords(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)
@@ -351,7 +355,7 @@ func TestMyCommissionService_ListMyCommissionRecords(t *testing.T) {
 		}
 		shop.Creator = 1
 		shop.Updater = 1
-		err := db.Create(shop).Error
+		err := tx.Create(shop).Error
 		require.NoError(t, err)
 
 		ctx := createMyCommissionTestContext(1, shop.ID, constants.UserTypeAgent)