Struct HealthCheckRequest 

pub struct HealthCheckRequest {
    pub selection: HostSelection,
    pub config_override: Option<PathBuf>,
    pub format: OutputFormat,
    pub json_local: bool,
    pub password_override: Option<SecretString>,
    pub timeout_override: Option<TimeoutMs>,
    pub key_override: Option<String>,
    pub key_passphrase_override: Option<SecretString>,
    pub replace_host_key: bool,
    pub host_source: TargetSource,
}

Everything one health-check invocation needs.

Why a struct (B3)

The single-host and fan-out entry points each took nine positional parameters, four of them Option<String> / Option<SecretString> in a row. A transposed key path and passphrase compiles and only fails against a live host. too_many_arguments — the one lint that measures this — was suppressed on both, so the coupling never showed up in a green gate.

Fields

selection: HostSelection

Single host, explicit list, tag set or the whole registry.

config_override: Option<PathBuf>

Alternate config directory.

format: OutputFormat

Global output format.

json_local: bool

Subcommand-local --json.

password_override: Option<SecretString>

SSH password override.

timeout_override: Option<TimeoutMs>

Connect timeout override.

key_override: Option<String>

Private key path override.

key_passphrase_override: Option<SecretString>

Key passphrase override.

replace_host_key: bool

Replace a diverging host key in TOFU known_hosts.

host_source: TargetSource

How the checked host was designated.

Since the --use-active opt-in landed, a nameless health-check is a usage error rather than a silent fallback. Provenance is still reported: it is what separates “I checked the host you named” from “I checked whatever connect last wrote”, and only the field distinguishes those after the run.