hermes photon setup unconditionally called regenerate_project_secret()
on every re-run, invalidating the credential held by a running sidecar
and causing all outbound sends to fail with AuthenticationError.
Now validates existing credentials via a lightweight list_users call
before deciding to regenerate. Only rotates when no credentials exist
or the existing ones are invalid, and warns the user to restart the
gateway when rotation occurs.
Fixes#50755
liuhao1024
703de9bacb