-- Device lesson MP3 download via Caddy public path (xiaozhi-server still listens on 8003).

UPDATE `sys_params`
SET `param_value` = 'https://xiaozhi.illegalfm.com/lesson-audio',
    `remark` = '设备下载课文 MP3 的公网根（Caddy /lesson-audio* → 内网 8003）；磁盘 data/lesson_audio/{org_id}/，空机构 default_org'
WHERE `param_code` = 'server.lesson_audio_public_url';