Replace g_options_len and g_opt_str_len extern variables with
CLI_OPT_LEN and CLI_OPT_STR_LEN enum constants computed via X-macros.
Disables Variable Length Arrays (VLA) by enforcing the use of the -Wvla
flag in strict mode.
Extract CLI options into a reusable macro (CLI_OPTIONS_LIST) in cli_opt.h
and refactor handler_map.c to eliminate manual option array duplication.
Calculate g_has_len automatically from option definitions.
