Portable install: the binary installs itself; static builds on five architectures; root via sudo, doas or uid 0; every package manager; older systemd; no lsblk

- hamlab install / uninstall (internal/setup): systemd or OpenRC, elevates through
  sudo or doas, runs as the invoking user, sets or generates the password, names only
  journal groups that exist, waits for /healthz, reports an active firewalld/ufw.
  --purge and the data chown never touch a directory that isn't Ham Lab's alone.
- install.sh: curl-able bootstrap (arch detection, SHA256SUMS, offline beside the
  binaries, noexec /tmp fallback). make release builds dist/ for amd64, arm64, arm
  (ARMv6), 386, riscv64. Every build is CGO_ENABLED=0; the native one used to link glibc.
- internal/priv replaces every literal `sudo -n`: uid 0, sudo or doas.
- Updates acts on dnf, zypper, pacman and apk as well as apt; dnf shows installed versions.
- Services falls back to the plain systemctl table before systemd 246 and says so on
  hosts without systemd. Disks falls back to /sys/block without lsblk.
- Listener binds with IP_FREEBIND, so a LAN address that isn't up at boot is no failure.
- Self-update: the new build must pass `check` against the live config, is put in
  place by atomic rename, and the daemon re-execs itself (same under any supervisor).
- State and config writes are fsynced; a corrupt state.json is set aside, not fatal.
- Terminal shutdown no longer empties the saved list, so names come back after a
  restart by design rather than by winning a race.
- Config default is ~/.config/hamlab; an existing ~/apps/hamlab is still found.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/setup/hamlab.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=Ham Lab web console
+After=network.target
+# never give up restarting
+StartLimitIntervalSec=0
+
+[Service]
+Type=simple
+User=@USER@
+Group=@GROUP@
+# read the system journal without sudo (keeps the daemon's own log clean)
+SupplementaryGroups=@GROUPS@
+WorkingDirectory=-@HOME@
+Environment=HAMLAB_CONFIG=@CONFIG@
+ExecStart=@BIN@ serve
+Restart=always
+RestartSec=3
+KillMode=control-group
+TimeoutStopSec=10
+LimitNOFILE=65536
+
+[Install]
+WantedBy=multi-user.target