Function run_validator 

pub fn run_validator<R: CommandRunner>(
    runner: &R,
    script_path: &str,
    json_input: &str,
    assertions: Option<&str>,
    expect: Option<&str>,
    container_stderr: Option<&str>,
) -> Result<HostValidationResult>

Run a validator script on the host with JSON input.

Arguments

• runner - Command runner for executing scripts (enables mocking)
• script_path - Path to validator script (e.g., “validators/validate-sqlite.sh”)
• json_input - JSON output from container to validate
• assertions - Optional assertion rules
• expect - Optional expected output
• container_stderr - Optional stderr output from container (for warning detection)

Errors

Returns error if the validator script cannot be spawned or if stdin write fails.