Export Csv

The list as a spreadsheet: subscribed addresses unless asked otherwise. The same columns for either list; alerts_sent is the row's alertsSent, so on the weekly deals the digests it was sent.

UTF-8, RFC 4180 (CRLF, fields quoted where they need it), formula-safe. Streamed from a server-side cursor, so a large list is never held in memory whole. The query runs before the answer starts, so a failure is still a plain 500 rather than a cut-off file.