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/app/app.go

@@ -33,12 +33,13 @@ var (
 )
 
 type App struct {
-	network  networkManager
-	services serviceManager
-	exports  exportManager
-	tools    toolManager
-	sat      satRunner
-	runtime  runtimeChecker
+	network   networkManager
+	services  serviceManager
+	exports   exportManager
+	tools     toolManager
+	sat       satRunner
+	runtime   runtimeChecker
+	installer installer
 }
 
 type ActionResult struct {
@@ -70,6 +71,11 @@ type toolManager interface {
 	CheckTools(names []string) []platform.ToolStatus
 }
 
+type installer interface {
+	ListInstallDisks() ([]platform.InstallDisk, error)
+	InstallToDisk(ctx context.Context, device string, logFile string) error
+}
+
 type satRunner interface {
 	RunNvidiaAcceptancePack(baseDir string) (string, error)
 	RunNvidiaAcceptancePackWithOptions(ctx context.Context, baseDir string, diagLevel int, gpuIndices []int) (string, error)
@@ -91,12 +97,13 @@ type runtimeChecker interface {
 
 func New(platform *platform.System) *App {
 	return &App{
-		network:  platform,
-		services: platform,
-		exports:  platform,
-		tools:    platform,
-		sat:      platform,
-		runtime:  platform,
+		network:   platform,
+		services:  platform,
+		exports:   platform,
+		tools:     platform,
+		sat:       platform,
+		runtime:   platform,
+		installer: platform,
 	}
 }
 
@@ -1003,3 +1010,11 @@ func firstNonEmpty(values ...string) string {
 	}
 	return ""
 }
+
+func (a *App) ListInstallDisks() ([]platform.InstallDisk, error) {
+	return a.installer.ListInstallDisks()
+}
+
+func (a *App) InstallToDisk(ctx context.Context, device string, logFile string) error {
+	return a.installer.InstallToDisk(ctx, device, logFile)
+}