nuc-seed.md -> nas-seed.md. The leg was designed around nuc's USB pool,
which is exactly the device it must not depend on. Target pool ks4backup
now lives on tank; nas becomes WG peer 10.8.0.22 and nuc's tunnel retires
once seeded — nuc no longer needs one at all, since transmission-bt (the
only other user) moved to nas with its own in-container tunnel.
ks4 needs no change: traffic arrives masqueraded as the wireguard
container whichever peer sent it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>