Drive the section title from the filename instead of the JS display-override
added earlier: rename configs/backup/backup_advanced -> backup_engine, update
the category SUBCATEGORY_ORDER and the file's header comment, and revert the
formatSubcategoryName override. The CFG_BACKUP_* keys are unchanged.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>
