fix: replace build_bee_debug with proper apkovl mechanism for Alpine LiveCD

- genapkovl-bee_debug.sh: creates apkovl tarball with overlay files,
  /etc/apk/world package list, runlevel symlinks, dropbear config
- mkimg.bee_debug.sh: set hostname/apkovl, remove invalid build_bee_debug

iso/builder/mkimg.bee_debug.sh

@@ -1,12 +1,12 @@
 #!/bin/sh
 # Alpine mkimage profile: bee_debug
-# Minimal LiveCD with audit binary + SSH for development/testing.
-# No NVIDIA driver. SSH root login enabled.
 
 profile_bee_debug() {
     title="Bee Hardware Audit (debug)"
     desc="Hardware audit LiveCD with SSH access for testing"
     arch="x86_64"
+    hostname="alpine-bee"
+    apkovl="genapkovl-bee_debug.sh"
     image_ext="iso"
     output_format="iso"
     kernel_flavors="lts"
@@ -43,21 +43,4 @@ profile_bee_debug() {
         less
         vim
     "
-
-    # overlay is applied after package install
-    # contains: audit binary, dropbear init, authorized_keys
-}
-
-build_bee_debug() {
-    # BEE_OVERLAY_DIR is exported by build-debug.sh (absolute path).
-    local overlay="${BEE_OVERLAY_DIR}"
-    if [ -d "$overlay" ]; then
-        cp -r "${overlay}/." "${ROOTFS}/"
-    fi
-
-    # enable services
-    _bootscript default bee-sshsetup
-    _bootscript default dropbear
-    _bootscript default bee-network
-    _bootscript default bee-audit-debug
 }