Match the skyw storage VLAN end-to-end:
  cisco Po4 (switch port-channel):  9216
  skydick (bond0 + skyw VLAN):      9200  ← this commit
  door-pek (bond0 + skyw VLAN):     9200

The 9000 → 9200 bump leaves 16 bytes of headroom under cisco Po4 9216
for VLAN tag + L2 overhead.

Pairs with nix-infra commit 0xxxxxxx (door-pek/networking: skyw VLAN
MTU 9200 jumbo frames).

Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>