feat(installer): add 'Install to disk' in Tools submenu

Copies the live system to a local disk via unsquashfs — no debootstrap,
no network required. Supports UEFI (GPT+EFI) and BIOS (MBR) layouts.

ISO:
- Add squashfs-tools, parted, grub-pc, grub-efi-amd64 to package list
- New overlay script bee-install: partitions, formats, unsquashfs,
  writes fstab, runs grub-install+update-grub in chroot

Go TUI:
- Settings → Tools submenu (Install to disk, Check tools)
- Disk picker screen: lists non-USB, non-boot disks via lsblk
- Confirm screen warns about data loss
- Runs with live progress tail of /tmp/bee-install.log
- platform/install.go: ListInstallDisks, InstallToDisk, findLiveBootDevice

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/tui/sat_progress.go

@@ -123,6 +123,26 @@ func cleanSATStepName(name string) string {
 	return name
 }
 
+// pollInstallProgress tails the install log file and returns recent lines as progress.
+func pollInstallProgress(logFile string) tea.Cmd {
+	return tea.Tick(500*time.Millisecond, func(_ time.Time) tea.Msg {
+		return satProgressMsg{lines: readInstallProgressLines(logFile)}
+	})
+}
+
+func readInstallProgressLines(logFile string) []string {
+	raw, err := os.ReadFile(logFile)
+	if err != nil {
+		return nil
+	}
+	lines := strings.Split(strings.TrimSpace(string(raw)), "\n")
+	// Show last 12 lines
+	if len(lines) > 12 {
+		lines = lines[len(lines)-12:]
+	}
+	return lines
+}
+
 func fmtDurMs(ms int) string {
 	if ms < 1000 {
 		return fmt.Sprintf("%dms", ms)