Unraid API returns fsUsed=0 when a disk's filesystem is unmounted (spun
down). disks.ini keeps the last-known value in KB even after spindown —
use it as fallback when isSpinning=false and fsUsed=0. Also remove the
mounted-only guard in the ini fallback path (vv_disk_entry) for the same
reason. Stale comments in user_script_plug-in.sh and partnership_manager.sh
also cleaned up.