=== DF-0145 unmount leak (vfs.quota_enabled=1) ===
Test: mount tmpfs, populate RB-trees via vquotactl set-limit-uid, unmount.
Bug: vq_done() at vfs_quota.c:142-146 is an empty stub -> ac_unode/ac_gnode leaked.

mount-count BEFORE:       717
mounted tmpfs on /mnt/df0145_3 (vq_init ran)
populated 300/300 uid chunks on /mnt/df0145_3 (each -> unode_insert kmalloc M_MOUNT)
mount-count AFTER populate (300 uid chunks): 1018
unmounted (VFS_ACDONE -> vq_done stub ran)
mount-count AFTER unmount: 1017

RESULT: ~300 ac_unode (M_MOUNT) allocations survived unmount = LEAKED.