- Add FATAL (50) to LogLevel enum, LEVEL_MAP, and LEVEL_THEME (bright red #E74C3C)
- Drop legacy COLORS dict in favor of LEVEL_THEME RGB values + ANSI_RESET
- Replace hard-coded stacklevel=4 with _INTERNAL_FRAMES constant so caller
location is always correct regardless of call-chain depth
- Simplify _normalize_module_name by removing redundant path normalization
- Add fatal() to ModuleLogger, AzLogsLogger, and module-level API
- Lazily init _log in path_utils via _get_log() to avoid circular imports