Download every diagram in the workspace with its whole history

Every diagram in the workspace the request acts in, with its whole history, in one JSON Lines file in the zindex-account-history/1 format. The first line is { format: "zindex-account-history/1", workspace: { id, name, kind }, exportedAt }, where kind is personal or team. Each diagram follows in ID order, exactly as GET /v1/diagrams/{id}/export writes it: a header line ({ format: "zindex-history/1", chain, id, key, title, revisions, note?, exportedAt }), then one line per version, oldest first. A line whose format is "zindex-history/1" starts the next diagram. The last line is { end: true, diagrams }, the number of diagrams in the file; a file without it was cut short. Deleted diagrams are left out, even while they can be restored. Each diagram's lines check on their own, like a diagram's export: https://zindex.ai/docs/concepts/#checking-an-export. A read key works too. In a team workspace only an owner can download it (403 OWNER_REQUIRED); everyone in it can still download one diagram's history at GET /v1/diagrams/{id}/export. The file is sent as a download (Content-Disposition: attachment), a line at a time as Zindex writes it.