/**
 * In-memory retain store for imported PowerPoint packages.
 * Enables future source-preserving writeback (Mona-style) without
 * regenerating untouched OOXML parts.
 */
export declare function retainSourcePackage(packageId: string, bytes: ArrayBuffer): void;
export declare function getSourcePackage(packageId: string): ArrayBuffer | undefined;
export declare function hasSourcePackage(packageId: string): boolean;
export declare function clearSourcePackage(packageId: string): void;
export declare function clearAllSourcePackages(): void;
export declare function markSourcePackageDirty(): void;
export declare function isSourcePackageClean(packageId?: string): boolean;
export declare function getActiveSourcePackageId(): string | null;
/**
 * Hybrid export fast-path: return retained bytes when the deck is still clean.
 */
export declare function tryGetCleanRetainedPackage(slides: Array<{
    sourcePackageId?: string;
}>): ArrayBuffer | null;