severity_mapper

/**
 * Create a SeverityMapper for mapping Monolog levels to Telemetry severities.
 *
 * @param null|array<int, Severity> $customMapping Optional custom mapping (Monolog Level value => Telemetry Severity)
 *
 * Example with default mapping:
 * ```php
 * $mapper = severity_mapper();
 * ```
 *
 * Example with custom mapping:
 * ```php
 * use Monolog\Level;
 * use Flow\Telemetry\Logger\Severity;
 *
 * $mapper = severity_mapper([
 *     Level::Debug->value => Severity::DEBUG,
 *     Level::Info->value => Severity::INFO,
 *     Level::Notice->value => Severity::WARN,  // Custom: NOTICE → WARN instead of INFO
 *     Level::Warning->value => Severity::WARN,
 *     Level::Error->value => Severity::ERROR,
 *     Level::Critical->value => Severity::FATAL,
 *     Level::Alert->value => Severity::FATAL,
 *     Level::Emergency->value => Severity::FATAL,
 * ]);
 * ```
 */
severity_mapper(?array $customMapping) : SeverityMapper