The poller's lock file in /tmp could be left owned by another user after a
manual run, leaving cron unable to open it. Lock the script file instead.
SETUP.md walks through installing the site on Yunohost, including the
/etc/cron.d entry for the poller, which was missing on the server and left
the recently played list empty.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>