Prune legacy void/alpine + customize.sh flows

The golden-image Dockerfile + catalog pipeline replaces the entire
manual rootfs-build stack. With that shipped, the per-distro shell
flows are dead code.

Removed:
- scripts/customize.sh, scripts/interactive.sh, scripts/verify.sh
- scripts/make-rootfs{,-void,-alpine}.sh
- scripts/register-{void,alpine}-image.sh
- scripts/make-{void,alpine}-kernel.sh
- internal/imagepreset/ (only consumer was `banger internal packages`,
  which fed customize.sh)
- examples/{void,alpine}.config.toml
- Makefile targets: rootfs, rootfs-void, rootfs-alpine, void-kernel,
  alpine-kernel, void-register, alpine-register, void-vm, alpine-vm,
  verify-void, verify-alpine, plus the ALPINE_RELEASE / *_IMAGE_NAME
  / *_VM_NAME variables

The void-6.12 kernel catalog entry is also gone — golden image pairs
with generic-6.12 and nothing else in the catalog depended on it.

Consolidated: imagemgr now holds the small DebianBasePackages list +
package-hash helper inline, so the `image build --from-image` flow
(still supported) no longer pulls from a separate imagepreset package.

Net: 3,815 lines deleted, 59 added. No runtime functionality removed
beyond the `banger internal packages` subcommand (hidden, used only
by the deleted customize.sh).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/cli/banger.go

@@ -30,7 +30,6 @@ import (
 	"banger/internal/guest"
 	"banger/internal/hostnat"
 	"banger/internal/imagecat"
-	"banger/internal/imagepreset"
 	"banger/internal/imagepull"
 	"banger/internal/model"
 	"banger/internal/paths"
@@ -219,7 +218,6 @@ func newInternalCommand() *cobra.Command {
 		newInternalSSHKeyPathCommand(),
 		newInternalFirecrackerPathCommand(),
 		newInternalVSockAgentPathCommand(),
-		newInternalPackagesCommand(),
 		newInternalMakeBundleCommand(),
 	)
 	return cmd
@@ -284,39 +282,6 @@ func newInternalVSockAgentPathCommand() *cobra.Command {
 	}
 }
 
-func newInternalPackagesCommand() *cobra.Command {
-	var docker bool
-	cmd := &cobra.Command{
-		Use:    "packages <debian|void|alpine>",
-		Hidden: true,
-		Args:   exactArgsUsage(1, "usage: banger internal packages <debian|void|alpine> [--docker]"),
-		RunE: func(cmd *cobra.Command, args []string) error {
-			var packages []string
-			switch strings.TrimSpace(args[0]) {
-			case "debian":
-				packages = imagepreset.DebianBasePackages()
-				if docker {
-					packages = append(packages, "docker.io")
-				}
-			case "void":
-				packages = imagepreset.VoidBasePackages()
-			case "alpine":
-				packages = imagepreset.AlpineBasePackages()
-			default:
-				return fmt.Errorf("unknown package preset %q", args[0])
-			}
-			for _, pkg := range packages {
-				if _, err := fmt.Fprintln(cmd.OutOrStdout(), pkg); err != nil {
-					return err
-				}
-			}
-			return nil
-		},
-	}
-	cmd.Flags().BoolVar(&docker, "docker", false, "include docker-specific additions")
-	return cmd
-}
-
 func newInternalMakeBundleCommand() *cobra.Command {
 	var (
 		rootfsTarPath string

internal/cli/cli_test.go

@@ -190,24 +190,6 @@ func TestInternalNATFlagsExist(t *testing.T) {
 	}
 }
 
-func TestInternalPackagesCommandSupportsAlpine(t *testing.T) {
-	cmd := NewBangerCommand()
-	var stdout bytes.Buffer
-	cmd.SetOut(&stdout)
-	cmd.SetArgs([]string{"internal", "packages", "alpine"})
-
-	if err := cmd.Execute(); err != nil {
-		t.Fatalf("Execute(): %v", err)
-	}
-
-	output := stdout.String()
-	for _, want := range []string{"alpine-base", "docker", "libgcc", "libstdc++", "mkinitfs", "openssh"} {
-		if !strings.Contains(output, want+"\n") {
-			t.Fatalf("output = %q, want package %q", output, want)
-		}
-	}
-}
-
 func TestPSAndVMListAliasesAndFlagsExist(t *testing.T) {
 	root := NewBangerCommand()
 	ps, _, err := root.Find([]string{"ps"})