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/screen_settings.go

@@ -44,17 +44,10 @@ func (m model) handleSettingsMenu() (tea.Model, tea.Cmd) {
 			result := m.app.AuditLogTailResult()
 			return resultMsg{title: result.Title, body: result.Body, back: screenSettings}
 		}
-	case 6: // Check tools
-		m.busy = true
-		m.busyTitle = "Check tools"
-		return m, func() tea.Msg {
-			result := m.app.ToolCheckResult([]string{
-				"dmidecode", "smartctl", "nvme", "ipmitool", "lspci",
-				"ethtool", "bee", "nvidia-smi", "bee-gpu-stress",
-				"memtester", "dhclient", "lsblk", "mount",
-			})
-			return resultMsg{title: result.Title, body: result.Body, back: screenSettings}
-		}
+	case 6: // Tools
+		m.screen = screenTools
+		m.cursor = 0
+		return m, nil
 	case 7: // Back
 		m.screen = screenMain
 		m.cursor = 0