Rewrites the Herdr doc to match what was actually built. The machine now
targets root@100.100.208.69 over Tailscale SSH instead of the LAN address,
so it no longer depends on the mikrotik-tailscale subnet router.
The "core did not start within 5 s" failure was the hc core socket living
under XDG_RUNTIME_DIR = /run/user/0, which pam_elogind creates and destroys
per login session. loginctl enable-linger root keeps that directory alive, so
every client agrees on the default socket path. The earlier Mac-side env pin
fixed the CLI but broke the GUI's plain-ssh "Add a machine"; linger
supersedes it and the wrapper is kept but unused.
Also records the stale ~/.ssh/config entry that pointed unraid at the deleted
100.100.208.70 on port 422, which is what the GUI had been listing, and the
go-script block that restores both the binary and linger at boot.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
