Function diagnosis 

fn diagnosis(
    error_code: &str,
    description: String,
    severity: DiagnosisSeverity,
) -> DiagnosisResult

Create a standardized diagnosis result with consistent formatting.

This is the base builder for all diagnosis results in the journal scanner. Use journal_error for journal-specific errors with path prefixing.

Arguments

• error_code - Machine-readable error identifier.
• description - Human-readable error description.
• severity - Error severity level.