refactor(migration): 统一数据库迁移基类为 AbstractMigration

- 将所有迁移类继承自 Phinx\Migration\AbstractMigration
- 替换旧的 think\migration\Migrator 基类
- 更新相关的 use 语句引入 Phinx 类库
- 保持原有的迁移逻辑和方法签名不变
- 确保严格类型声明在文件顶部正确设置

database/migrations/20251010100100_create_shipping_template_rules_table.php

@@ -1,9 +1,9 @@
 <?php
 
-use think\migration\Migrator;
+use Phinx\Migration\AbstractMigration;
 use think\migration\db\Column;
 
-class CreateShippingTemplateRulesTable extends Migrator
+class CreateShippingTemplateRulesTable extends AbstractMigration
 {
     public function change()
     {

database/migrations/20251010100200_create_shipping_template_relations_table.php

@@ -1,9 +1,9 @@
 <?php
 
-use think\migration\Migrator;
+use Phinx\Migration\AbstractMigration;
 use think\migration\db\Column;
 
-class CreateShippingTemplateRelationsTable extends Migrator
+class CreateShippingTemplateRelationsTable extends AbstractMigration
 {
     public function change()
     {