0a6865b328
Covers PR #18256 fix for issue #18254 — when OPENROUTER_API_KEY is set in BOTH os.environ (stale from parent shell) and ~/.hermes/.env (fresh), _seed_from_env must prefer the .env value. Also guards the fallback case where .env omits the key entirely (Docker/K8s/systemd deployments that only inject via runtime env).