feat: add operator and business reference fields to tenant ledgers

- Added `operator_user_id`, `biz_ref_type`, and `biz_ref_id` fields to the TenantLedger model for enhanced auditing and traceability.
- Updated the tenant ledgers query generation to include new fields.
- Introduced new API endpoint for retrieving tenant ledger records with filtering options based on the new fields.
- Enhanced Swagger documentation to reflect the new endpoint and its parameters.
- Created DTOs for admin ledger filtering and item representation.
- Implemented the admin ledger retrieval logic in the tenant service.
- Added database migration scripts to introduce new fields and indexes for efficient querying.

backend/database/models/order_items.gen.go

@@ -28,8 +28,8 @@ type OrderItem struct {
 	Snapshot      types.JSONType[fields.OrderItemsSnapshot] `gorm:"column:snapshot;type:jsonb;not null;default:{};comment:内容快照：JSON；建议包含 title/price/discount 等，用于历史展示与审计" json:"snapshot"` // 内容快照：JSON；建议包含 title/price/discount 等，用于历史展示与审计
 	CreatedAt     time.Time                                 `gorm:"column:created_at;type:timestamp with time zone;not null;default:now();comment:创建时间：默认 now()" json:"created_at"`         // 创建时间：默认 now()
 	UpdatedAt     time.Time                                 `gorm:"column:updated_at;type:timestamp with time zone;not null;default:now();comment:更新时间：默认 now()" json:"updated_at"`         // 更新时间：默认 now()
-	Order         *Order                                    `gorm:"foreignKey:OrderID;references:ID" json:"order,omitempty"`
 	Content       *Content                                  `gorm:"foreignKey:ContentID;references:ID" json:"content,omitempty"`
+	Order         *Order                                    `gorm:"foreignKey:OrderID;references:ID" json:"order,omitempty"`
 }
 
 // Quick operations without importing query package