/**
 * Config migration — auto-upgrade old config formats to current schema.
 * Each migration has a version number and a transform function.
 */
export interface Migration {
    version: number;
    description: string;
    migrate: (config: Record<string, unknown>) => Record<string, unknown>;
}
/**
 * Ordered list of migrations. Each bumps configVersion by 1.
 */
export declare const MIGRATIONS: Migration[];
export declare const CURRENT_CONFIG_VERSION: number;
export interface MigrationResult {
    fromVersion: number;
    toVersion: number;
    applied: string[];
    config: Record<string, unknown>;
}
/**
 * Apply all pending migrations to a config object.
 */
export declare function migrateConfig(config: Record<string, unknown>): MigrationResult;
/**
 * Check if a config needs migration.
 */
export declare function needsMigration(config: Record<string, unknown>): boolean;
/**
 * Format migration result for display.
 */
export declare function formatMigrationResult(result: MigrationResult): string;
