feat: add starting script

#!/bin/sh

set -eu

DATA_DIR="${NEXTCLOUD_DATA_DIR:-/var/www/html/data}"

TARGET_FILE="${DATA_DIR}/appdata_snappymail/_data_/_default_/admin_password.txt"

if [ ! -d "${DATA_DIR}" ]; then

    echo "[before-starting] Nextcloud data directory \"${DATA_DIR}\" is missing; skipping SnappyMail admin password cleanup."

    return 0 2>/dev/null || exit 0

fi

if [ -f "${TARGET_FILE}" ]; then

    rm -f "${TARGET_FILE}"

    echo "[before-starting] Removed SnappyMail admin password file at ${TARGET_FILE}."

fi