python-module-level-env-read-bypasses-prod-safety

Module-level os.getenv('SECRET', 'dev-fallback') calls in Python execute at import time before runtime env changes apply and before any production-safety validator runs. The dev fallback (often a publicly known key) silently wins. Refactor to a lazy accessor function _get_secret() called at use-time, and add an explicit check that rejects dev-default values when ENV=production.