fix: 修改 public settings API公告字段类型为 dict

apps/settings/serializers/public.py

@@ -40,6 +40,6 @@ class PrivateSettingSerializer(PublicSettingSerializer):
     TERMINAL_KOKO_SSH_ENABLED = serializers.BooleanField()
 
     ANNOUNCEMENT_ENABLED = serializers.BooleanField()
-    ANNOUNCEMENT = serializers.CharField()
+    ANNOUNCEMENT = serializers.DictField()
     
     TICKETS_ENABLED = serializers.BooleanField()