feat：移除了弹窗，服务器添加sls

packages/app-lib/migrations/20260816120000_download_engine_setting.sql

@@ -0,0 +1,8 @@
+ALTER TABLE settings
+	ADD COLUMN download_engine TEXT NOT NULL DEFAULT 'xmcl';
+
+UPDATE settings
+SET download_engine = CASE
+	WHEN json_extract(feature_flags, '$.xmcl_download_engine') = 0 THEN 'legacy'
+	ELSE 'xmcl'
+END;