- image-versions.sh: fix 15+ tag mismatches against actual registry
(bitcoin-knots:28.1→latest, lnd:v0.18.5→v0.18.4, grafana:11.4→10.2,
vaultwarden:1.32.5→1.30.0-alpine, nextcloud:29→28, etc.)
- .bashrc: add /sbin:/usr/sbin to PATH so reboot/shutdown work
- Tailscale: add Arch Atob node (100.113.33.31)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>