Add initramfs-level Drive Wipe tool (bee.wipe=all)

Installs a local-premount initramfs hook that intercepts bee.wipe=all before
squashfs is mounted. Shows a numbered disk selection TUI (pure POSIX sh), wipes
selected disks (nvme format / blkdiscard / dd fallback), syncs, and reboots.
Works even when squashfs fails to mount.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

iso/builder/config/hooks/normal/9012-wipe.hook.chroot

@@ -0,0 +1,57 @@
+#!/bin/sh
+# 9012-wipe.hook.chroot
+#
+# Adds bee-initramfs-wipe to the initramfs so that selecting the
+# "WIPE ALL DISKS" boot menu entry runs the wipe tool before squashfs
+# is mounted — i.e. it works even when live boot fails.
+#
+# Two files are installed inside the chroot:
+#   /etc/initramfs-tools/hooks/bee-wipe         — copies binaries into initrd
+#   /etc/initramfs-tools/scripts/local-premount/bee-wipe — runs at boot
+
+set -e
+
+HOOK_DIR="/etc/initramfs-tools/hooks"
+SCRIPT_DIR="/etc/initramfs-tools/scripts/local-premount"
+
+mkdir -p "${HOOK_DIR}" "${SCRIPT_DIR}"
+
+# ── initramfs hook: copy binaries ────────────────────────────────────────────
+cat > "${HOOK_DIR}/bee-wipe" << 'EOF'
+#!/bin/sh
+PREREQ=""
+prereqs() { echo "$PREREQ"; }
+case "$1" in prereqs) prereqs; exit 0 ;; esac
+
+. /usr/share/initramfs-tools/hook-functions
+
+for bin in lsblk blkid blkdiscard blockdev; do
+    b=$(command -v "$bin" 2>/dev/null) && copy_exec "$b" /bin
+done
+
+[ -x /usr/sbin/nvme ] && copy_exec /usr/sbin/nvme /sbin
+
+copy_exec /usr/local/bin/bee-initramfs-wipe /bin/bee-wipe
+EOF
+
+chmod +x "${HOOK_DIR}/bee-wipe"
+
+# ── initramfs premount script: trigger on bee.wipe=all ───────────────────────
+cat > "${SCRIPT_DIR}/bee-wipe" << 'EOF'
+#!/bin/sh
+PREREQ=""
+prereqs() { echo "$PREREQ"; }
+case "$1" in prereqs) prereqs; exit 0 ;; esac
+
+grep -qw 'bee.wipe=all' /proc/cmdline 2>/dev/null || exit 0
+exec /bin/bee-wipe
+EOF
+
+chmod +x "${SCRIPT_DIR}/bee-wipe"
+
+echo "9012-wipe: installed initramfs hook and premount script"
+
+KVER=$(ls /lib/modules | sort -V | tail -1)
+echo "9012-wipe: rebuilding initramfs for kernel ${KVER}"
+update-initramfs -u -k "${KVER}"
+echo "9012-wipe: done"