Add should_use_color() function to hermes_cli/colors.py that checks
NO_COLOR (https://no-color.org/) and TERM=dumb before emitting ANSI
escapes. The existing color() helper now uses this function instead
of a bare isatty() check.
This is the foundation — cli.py and banner.py still have inline ANSI
constants that bypass this module (tracked in #4071).
Closes#4066
Co-authored-by: SHL0MS <SHL0MS@users.noreply.github.com>