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/platform/install.go

@@ -0,0 +1,105 @@
+package platform
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+// InstallDisk describes a candidate disk for installation.
+type InstallDisk struct {
+	Device string // e.g. /dev/sda
+	Model  string
+	Size   string // human-readable, e.g. "500G"
+}
+
+// ListInstallDisks returns block devices suitable for installation.
+// Excludes USB drives and the current live boot medium.
+func (s *System) ListInstallDisks() ([]InstallDisk, error) {
+	out, err := exec.Command("lsblk", "-dn", "-o", "NAME,MODEL,SIZE,TYPE,TRAN").Output()
+	if err != nil {
+		return nil, fmt.Errorf("lsblk: %w", err)
+	}
+
+	bootDev := findLiveBootDevice()
+
+	var disks []InstallDisk
+	for _, line := range strings.Split(strings.TrimSpace(string(out)), "\n") {
+		fields := strings.Fields(line)
+		// NAME MODEL SIZE TYPE TRAN  — model may have spaces so we parse from end
+		if len(fields) < 4 {
+			continue
+		}
+		// Last field: TRAN, second-to-last: TYPE, third-to-last: SIZE
+		tran := fields[len(fields)-1]
+		typ := fields[len(fields)-2]
+		size := fields[len(fields)-3]
+		name := fields[0]
+		model := strings.Join(fields[1:len(fields)-3], " ")
+
+		if typ != "disk" {
+			continue
+		}
+		if strings.EqualFold(tran, "usb") {
+			continue
+		}
+
+		device := "/dev/" + name
+		if device == bootDev {
+			continue
+		}
+
+		disks = append(disks, InstallDisk{
+			Device: device,
+			Model:  strings.TrimSpace(model),
+			Size:   size,
+		})
+	}
+	return disks, nil
+}
+
+// findLiveBootDevice returns the block device backing /run/live/medium (if any).
+func findLiveBootDevice() string {
+	out, err := exec.Command("findmnt", "-n", "-o", "SOURCE", "/run/live/medium").Output()
+	if err != nil {
+		return ""
+	}
+	src := strings.TrimSpace(string(out))
+	if src == "" {
+		return ""
+	}
+	// Strip partition suffix to get the whole disk device.
+	// e.g. /dev/sdb1 → /dev/sdb,  /dev/nvme0n1p1 → /dev/nvme0n1
+	out2, err := exec.Command("lsblk", "-no", "PKNAME", src).Output()
+	if err != nil || strings.TrimSpace(string(out2)) == "" {
+		return src
+	}
+	return "/dev/" + strings.TrimSpace(string(out2))
+}
+
+// InstallToDisk runs bee-install <device> <logfile> and streams output to logFile.
+// The context can be used to cancel.
+func (s *System) InstallToDisk(ctx context.Context, device string, logFile string) error {
+	cmd := exec.CommandContext(ctx, "bee-install", device, logFile)
+	return cmd.Run()
+}
+
+// InstallLogPath returns the default install log path for a given device.
+func InstallLogPath(device string) string {
+	safe := strings.NewReplacer("/", "_", " ", "_").Replace(device)
+	return "/tmp/bee-install" + safe + ".log"
+}
+
+// DiskLabel returns a display label for a disk.
+func (d InstallDisk) Label() string {
+	model := d.Model
+	if model == "" {
+		model = "Unknown"
+	}
+	sizeBytes, err := strconv.ParseInt(strings.TrimSuffix(d.Size, "B"), 10, 64)
+	_ = sizeBytes
+	_ = err
+	return fmt.Sprintf("%s  %s  %s", d.Device, d.Size, model)
+}