Extend the Django logs view with filters for service unit, severity, time
window, host, run id, and message text. Pass severity and time window directly
to journalctl, then apply host/run/message filtering to the returned pobsync
journal lines.
This makes failed or slow backups easier to investigate from the control panel
without needing shell access.
Restructure the run detail page into clearer sections for summary, failure
classification, requested options, rsync command, rsync log output, stats,
retention, and raw result data.
Show recent rsync log output inline with a link to the full log, and promote
failure and retention warning details out of the JSON payload so failed or slow
runs are easier to debug from the control panel.
