/// Abstraction over the external file storage backend (Nextcloud via WebDAV,
/// or S3-compatible object storage). Implementations only need to move raw
/// bytes; visibility/ownership metadata lives in the `File` Prisma model.
export interface StorageProvider {
  upload(kcId: string, filename: string, data: Buffer): Promise<string>;
  download(storageKey: string): Promise<Buffer>;
  delete(storageKey: string): Promise<void>;
}

export const STORAGE_PROVIDER = Symbol('STORAGE_PROVIDER');