* Example usage:
     * </p>
     * <pre>
     * Path baseDir = Paths.get("/var/app/data");
     * Path userPath = Paths.get(userInput);
     * if (!FileUtil.isPathSafe(userPath, baseDir)) {
     *     throw new SecurityException("Path traversal attempt detected");
     * }
     * </pre>
     *
     * @param pathToCheck the path to validate (must not be {@literal null})