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/daemon/imagemgr/paths.go

@@ -8,14 +8,44 @@ package imagemgr
 
 import (
 	"context"
+	"crypto/sha256"
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
 
-	"banger/internal/imagepreset"
 	"banger/internal/system"
 )
 
+// debianBasePackages is the apt package list applied by
+// `image build --from-image` to Debian-based managed rootfses. Small
+// curated set: most of the developer tooling the golden image ships
+// lives in the Dockerfile, not here.
+var debianBasePackages = []string{
+	"make",
+	"git",
+	"less",
+	"tree",
+	"ca-certificates",
+	"curl",
+	"wget",
+	"iproute2",
+	"vim",
+	"tmux",
+}
+
+// DebianBasePackages returns a copy of the base package set.
+func DebianBasePackages() []string {
+	return append([]string(nil), debianBasePackages...)
+}
+
+// hashPackages returns the hex sha256 of the package list, used as
+// drift-detection metadata alongside a built rootfs.
+func hashPackages(lines []string) string {
+	sum := sha256.Sum256([]byte(strings.Join(lines, "\n") + "\n"))
+	return fmt.Sprintf("%x", sum)
+}
+
 // ValidateRegisterPaths checks that rootfs + kernel exist and that optional
 // artifacts, when provided, also exist.
 func ValidateRegisterPaths(rootfsPath, workSeedPath, kernelPath, initrdPath, modulesDir string) error {
@@ -102,7 +132,7 @@ func StageOptionalArtifactPath(artifactDir, stagedPath, name string) string {
 // managed image build. The #feature:docker sentinel is appended when
 // docker is requested.
 func BuildMetadataPackages(docker bool) []string {
-	packages := imagepreset.DebianBasePackages()
+	packages := DebianBasePackages()
 	if docker {
 		packages = append(packages, "#feature:docker")
 	}
@@ -116,5 +146,5 @@ func WritePackagesMetadata(rootfsPath string, packages []string) error {
 		return nil
 	}
 	metadataPath := rootfsPath + ".packages.sha256"
-	return os.WriteFile(metadataPath, []byte(imagepreset.Hash(packages)+"\n"), 0o644)
+	return os.WriteFile(metadataPath, []byte(hashPackages(packages)+"\n"), 0o644)
 }

internal/daemon/images.go

@@ -11,7 +11,6 @@ import (
 
 	"banger/internal/api"
 	"banger/internal/daemon/imagemgr"
-	"banger/internal/imagepreset"
 	"banger/internal/kernelcat"
 	"banger/internal/model"
 	"banger/internal/system"
@@ -86,7 +85,7 @@ func (d *Daemon) BuildImage(ctx context.Context, params api.ImageBuildParams) (i
 	if err != nil {
 		return model.Image{}, err
 	}
-	packages := imagepreset.DebianBasePackages()
+	packages := imagemgr.DebianBasePackages()
 	metadataPackages := imagemgr.BuildMetadataPackages(params.Docker)
 	spec := imageBuildSpec{
 		ID:            id,