拆分 service 与前端大文件,修复 CORS 配置与格式问题

- 后端 internal/service 按职责拆分:
  fulfillment.go(1397→527)拆出 wallet/timeout/data/order/query/dashboard/shipnotify
  delivery.go(1124→801)拆出 upstream/link/state/helpers
  merchant.go(855→251)拆出 member/product/api_client/catalog/helpers
- 前端 MerchantCenter.tsx(1327→606)拆出 merchantCenterTabs/merchantCenterUtils
- docker-compose backend 透传 CORS_ALLOWED_ORIGINS
- CORS 白名单实现(config/router/README/.env.example 配套)
- 修复 gofmt 与文件尾部多余空行

backend/internal/service/fulfillment_wallet.go

@@ -0,0 +1,110 @@
+package service
+
+import (
+	"errors"
+	"fmt"
+
+	"affiliate_dash/internal/model"
+
+	"github.com/google/uuid"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+type WalletAdjustInput struct {
+	MerchantID     uint
+	ActorUserID    uint
+	Amount         int64
+	IdempotencyKey string
+	Note           string
+}
+
+func (s *FulfillmentService) AdjustWallet(in WalletAdjustInput) (*model.WalletAccount, error) {
+	if in.Amount == 0 {
+		return nil, errors.New("调整金额不能为零")
+	}
+	if in.IdempotencyKey == "" {
+		return nil, errors.New("账务调整必须提供幂等键")
+	}
+	var out model.WalletAccount
+	err := s.db.Transaction(func(tx *gorm.DB) error {
+		var existing model.WalletLedgerEntry
+		if err := tx.Where("merchant_id = ? AND idempotency_key = ?", in.MerchantID, in.IdempotencyKey).First(&existing).Error; err == nil {
+			if err := tx.First(&out, existing.WalletAccountID).Error; err != nil {
+				return err
+			}
+			return nil
+		} else if !errors.Is(err, gorm.ErrRecordNotFound) {
+			return err
+		}
+
+		var wallet model.WalletAccount
+		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).Where("merchant_id = ?", in.MerchantID).First(&wallet).Error; err != nil {
+			return err
+		}
+		newBalance := wallet.AvailableBalance + in.Amount
+		if newBalance < 0 {
+			return errors.New("调整后余额不能小于零")
+		}
+		if err := tx.Model(&wallet).Update("available_balance", newBalance).Error; err != nil {
+			return err
+		}
+		entryType := model.WalletLedgerAdjust
+		if in.Amount > 0 {
+			entryType = model.WalletLedgerCredit
+		} else {
+			entryType = model.WalletLedgerDebit
+		}
+		idempotencyKey := in.IdempotencyKey
+		if err := tx.Create(&model.WalletLedgerEntry{
+			MerchantID:      in.MerchantID,
+			WalletAccountID: wallet.ID,
+			EntryNo:         "WL" + uuid.NewString(),
+			Type:            entryType,
+			Amount:          in.Amount,
+			BalanceAfter:    newBalance,
+			ReferenceType:   "manual_adjustment",
+			ReferenceNo:     in.IdempotencyKey,
+			IdempotencyKey:  &idempotencyKey,
+			Note:            in.Note,
+		}).Error; err != nil {
+			return err
+		}
+		out = wallet
+		out.AvailableBalance = newBalance
+		return writeAudit(tx, &in.MerchantID, &in.ActorUserID, nil, "wallet.adjust", "wallet_account", fmt.Sprint(wallet.ID), map[string]int64{"amount": in.Amount})
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &out, nil
+}
+
+func (s *FulfillmentService) GetWallet(merchantID uint) (*model.WalletAccount, error) {
+	var wallet model.WalletAccount
+	if err := s.db.Where("merchant_id = ?", merchantID).First(&wallet).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, errors.New("商户钱包不存在")
+		}
+		return nil, err
+	}
+	return &wallet, nil
+}
+
+func (s *FulfillmentService) ListWalletLedger(merchantID uint, page, size int, referenceNo, entryType string) ([]model.WalletLedgerEntry, int64, error) {
+	page, size = normalizePage(page, size)
+	tx := s.db.Model(&model.WalletLedgerEntry{}).Where("merchant_id = ?", merchantID)
+	if referenceNo != "" {
+		tx = tx.Where("reference_no LIKE ?", "%"+referenceNo+"%")
+	}
+	if entryType != "" {
+		tx = tx.Where("type = ?", entryType)
+	}
+	var total int64
+	if err := tx.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+	var entries []model.WalletLedgerEntry
+	err := tx.Order("id DESC").Offset((page - 1) * size).Limit(size).Find(&entries).Error
+	return entries, total, err
+}