Salvaged from #56982 (@rayjun): the live piece of the PR. The
hermes_cli/config.py get_env_value scope-honoring change and its
test_env_load_cache.py tests were already merged via ed1170cd8b
(#76462) and are dropped here.
tools/xai_http.py::get_env_value wrapped the scope-aware
hermes_cli.config.get_env_value in except Exception + a raw os.environ
fallback — swallowing UnscopedSecretError and borrowing the process
env, so a multiplexed xAI credential read could silently pick up
another profile's XAI_API_KEY. Narrow the except to ImportError (the
only legitimate degraded case) so get_secret's verdict propagates: an
unscoped multiplexed read fails closed, and a scoped miss returns the
default instead of the foreign environ value.
Co-authored-by: rayjun <rayjun0412@gmail.com>