## USB drives now work out of the box (exFAT / NTFS / FAT + storage)

Plug a USB drive into the gateway and it mounts — no `owut`/`apk` install step
first. Previously the lean image shipped removable-media support as
installable-only (`=m`), and the USB xHCI host driver wasn't baked at all, so a
stock image couldn't even enumerate a USB device.

Now baked into the image:

- **USB host + storage** — kmod-usb3 (xHCI), kmod-usb-storage (+ UAS), SCSI
- **Filesystems** — exFAT, NTFS3, FAT/vFAT, plus the NLS codepages (cp437,
  iso8859-1, utf8)

btrfs and ext4 stay installable-only (ext4 is kernel-builtin; btrfs is large and
rarely on removable media). Image grows ~300 KB. No configuration changes.

> Upgrade with **`owut upgrade`** (preserves installed packages).