/** @purpose Project-wide logger contract with a stable debug/info/warn/error API. */
export type SimpleLogger = {
    /**
     * @purpose Emits a debug-level message for development diagnostics.
     * @param message Log message with Trace-Prefix and state transition.
     * @param [detail] Optional structured payload.
     */
    debug: (message: string, detail?: unknown) => void;
    /**
     * @purpose Emits an info-level message for normal operational events.
     * @param message Log message with Trace-Prefix and state transition.
     * @param [detail] Optional structured payload.
     */
    info: (message: string, detail?: unknown) => void;
    /**
     * @purpose Emits a warning-level message for non-fatal issues.
     * @param message Log message with Trace-Prefix and state transition.
     * @param [detail] Optional structured payload.
     */
    warn: (message: string, detail?: unknown) => void;
    /**
     * @purpose Emits an error-level message for failures requiring investigation.
     * @param message Log message with Trace-Prefix and state transition.
     * @param [detail] Optional structured payload.
     */
    error: (message: string, detail?: unknown) => void;
};
/** @purpose Ordered log levels — lower index = more verbose. */
export type LogLevel = 'debug' | 'info' | 'warn' | 'error' | 'silent';
/** @purpose Set the minimum log level for the global logger instance. */
export declare const setLogLevel: (level: LogLevel) => void;
/**
 * @purpose Logger implementation bound to the runtime console, filtered by the active log level.
 * @sideEffect Console: writes log entries to stderr via console methods.
 */
export declare const logger: SimpleLogger;