优化钱包界面：改名积分明细，添加筛选功能，优化表格列宽

- 侧边栏和页面标题改为'积分明细'
- 新增关联单号、收支类型筛选功能
- 后端 ledger API 支持 reference_no 和 type 筛选参数
- 表格列宽优化，流水号完整展示，备注列限制宽度
- 隐藏固定 tab 模式下的商户介绍文字

backend/internal/service/fulfillment.go

@@ -694,9 +694,15 @@ func (s *FulfillmentService) GetWallet(merchantID uint) (*model.WalletAccount, e
 	return &wallet, nil
 }
 
-func (s *FulfillmentService) ListWalletLedger(merchantID uint, page, size int) ([]model.WalletLedgerEntry, int64, error) {
+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