Function show_rule_structured 

pub fn show_rule_structured(
    root: &Path,
    id: &str,
    config: &RulesRunConfig,
) -> Result<RuleInfoReport, String>

Collect fact rule diagnostics without printing (returns raw diagnostics).

Performs a full evaluation via interpret::run_rules_batch. For the incremental path (daemon/LSP), use collect_fact_diagnostics_incremental instead. Structured variant of show_rule — returns a RuleInfoReport instead of a pre-formatted string. Used by rules show for machine-readable JSON output.