Function plugin_error_warn 

pub fn plugin_error_warn(
    plugin_name: &str,
    reason: impl Into<String>,
) -> Verdict

Construct a Verdict::Warn for a plugin infrastructure error. Plugin errors (non-zero exit, malformed JSON, timeout, unknown version) produce a Verdict::Warn with rule = KLASP_PLUGIN_RULE. The gate continues with the remaining checks — plugin errors never crash klasp.

The plugin name is prepended to the message so renderers and JUnit formatters can attribute the warning to a specific plugin.