v2.3.0

• add --bearer-token-env <name> for remote servers. fx writes it as bearer_token_env. Other agents drop it with a warning. When the same run also passes --header Authorization, fx omits that header, warns, and keeps bearer_token_env; other agents keep the header. Authorization without --bearer-token-env still fails on fx. Empty, whitespace, and non-identifier names fail in the CLI and the SDK.