sequenceDiagram
    participant B as Browser
    participant P as PageModel
    participant S as DocumentsService
    participant S3 as S3-Speicher

    B->>P: POST /documents?handler=Zip&keys=[...]
    P->>S: GetZipStreamAsync(orgId, keys)
    loop je Dokument
        S->>S3: GetObjectAsync(key)
        S3-->>S: Stream
        S->>S: ZipArchive.CreateEntry + CopyToAsync
    end
    S-->>P: ZipStream
    P-->>B: application/zip (streaming)