type FilePreviewKind = 'pdf' | 'excel' | 'text' | 'office' | 'unsupported';
export type MediaPreviewKind = FilePreviewKind | 'image' | 'video' | 'audio';
/** 按 URL / 文件名推断预览类型（含图片 / 音视频） */
export declare function getMediaPreviewKind(path?: string): MediaPreviewKind;
export declare function fileDisplayName(path?: string, fallback?: string): string;
export declare function fetchFileText(url: string): Promise<string>;
/** Excel 首表 → HTML 表格 */
export declare function loadExcelPreviewHtml(url: string): Promise<string>;
export {};
