core/init.py

# Phase A: empty __init__.py — no re-exports.
#
# Rationale (ARCH-P1-1):
#   Re-exporting from subpackages causes tight coupling, import-time side
#   effects (Settings singleton, structlog init), and future circular imports
#   when more modules are added under core/.
#
#   All imports must be explicit:
#     from core.config.settings import get_settings
#     from core.logging.logger import get_logger, setup_logging
#     from core.security.validators import validate_bot_token, validate_admin_id