feat(公开内容): 添加临时文件上传功能，支持1小时/1天/7天过期

core/models.py

@@ -240,6 +240,18 @@ class PublicContent(models.Model):
     url = models.URLField(blank=True, null=True, verbose_name="链接地址")
     sort_order = models.IntegerField(default=0, verbose_name="排序")
     is_published = models.BooleanField(default=True, verbose_name="是否发布")
+    is_temp_file = models.BooleanField(default=False, verbose_name="临时文件")
+    expire_type = models.CharField(
+        max_length=10,
+        choices=[
+            ('expire_1h', '1小时'),
+            ('expire_1d', '1天'),
+            ('expire_7d', '7天'),
+        ],
+        blank=True, null=True,
+        verbose_name="过期类型"
+    )
+    expire_at = models.DateTimeField(blank=True, null=True, verbose_name="过期时间")
     created_at = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")
     updated_at = models.DateTimeField(auto_now=True, verbose_name="更新时间")