Small thing but it got me last week. I relay my stream to twitch through nginx-rtmp on a cheap VPS, and one morning unattended-upgrades pulled a new systemd, needrestart restarted nginx (and postgres, and everything else) and the stream dropped. OBS reconnected fast but twitch counted it as two streams.
default timer is 06:00 UTC + up to 1h random, which is exactly when I stream lol. moved it with a drop-in:
# systemctl edit apt-daily-upgrade.timer
[Timer]
OnCalendar=
OnCalendar=*-*-* 13:45:00 UTC
RandomizedDelaySec=15m
the empty OnCalendar= matters, without it you just add a second time and keep the old one.
anyone else got bitten by this?

Plan sounds fine to me, debian + immich in docker + tailscale is pretty much the boring setup and boring is good for a box in a shed. one thing I’d do before carrying it out there, install tailscale and ssh, reboot it a couple of times and make sure it comes back on its own without a screen, because walking to the shed with a monitor gets old fast. also something like uptime kuma on another machine (or your NAS) pinging it, so you know it’s down before you’re on holiday and the photos stop uploading. I run a box at home I only reach over tailscale and that’s the part that saved me most.