- _quota_supported() checks df -T /srv; returns false + reason for ZFS, tmpfs, overlay — surfaces as quota_supported/quota_reason in dashboard API - Dashboard quota section shows the reason string instead of an empty table - Quota button hidden from share rows when quota_supported is false - Prevents setquota errors for ZFS-backed Proxmox LXC containers Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>