feat: add client release size bytes

apps/portal/models.py

@@ -1,5 +1,5 @@
 from django.core.exceptions import ValidationError
-from django.core.validators import RegexValidator
+from django.core.validators import MinValueValidator, RegexValidator
 from django.db import models, transaction
 
 
@@ -13,6 +13,13 @@ class DownloadRelease(models.Model):
     version = models.CharField("版本", max_length=64)
     file = models.FileField("安装包文件", upload_to="downloads/", blank=True)
     external_url = models.URLField("外部下载地址", blank=True)
+    size_bytes = models.PositiveBigIntegerField(
+        "文件大小字节数",
+        null=True,
+        blank=True,
+        validators=[MinValueValidator(1)],
+        help_text="客户端下载文件大小，单位字节；桌面端用于下载后校验。",
+    )
     sha256 = models.CharField(
         "SHA256",
         max_length=64,