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/term/manager.go

@@ -9,6 +9,7 @@ import (
 	"os/exec"
 	"sort"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"time"
 
@@ -68,6 +69,7 @@ type Manager struct {
 	shell    string
 	home     string
 	OnChange func([]Info) // called (without locks held) when the list changes
+	closing  atomic.Bool
 }
 
 func NewManager(shell, home string) *Manager {
@@ -283,13 +285,15 @@ func (m *Manager) Close(id string) error {
 }
 
 func (m *Manager) changed() {
-	if m.OnChange != nil {
+	if m.OnChange != nil && !m.closing.Load() {
 		m.OnChange(m.List())
 	}
 }
 
-// Shutdown hangs up every shell. Called on daemon exit.
+// Shutdown hangs up every shell. Called on daemon exit. The saved list is left as it
+// was, because that list is what the next start re-opens.
 func (m *Manager) Shutdown() {
+	m.closing.Store(true)
 	for _, s := range m.List() {
 		_ = m.Close(s.ID)
 	}