feat(orm): upgrade think-orm to version 4.0 and add BaseEntity class

- Upgrade topthink/think-orm from ^3.0 to ^4.0 in composer.json
- Add new BaseEntity class in app/common/entity to handle common entity options

app/common/entity/BaseEntity.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace app\common\entity;
+
+use think\Entity;
+use think\model\type\DateTime;
+
+class BaseEntity extends Entity
+{
+
+    protected function getOptions(): array
+    {
+        return [
+            'type' => [
+                'create_time' => DateTime::class,
+                'update_time' => DateTime::class,
+                'delete_time' => DateTime::class,
+            ],
+        ];
+    }
+
+}