Scheduled weekly contact export

Let me set up an automatic export of my contacts (and optionally notes) on a schedule, for example once a week, instead of exporting by hand from Settings → Import / Export.

Current gap: exports are one-shot downloads only. The only way to get a recurring copy today is to pull contacts through the Dex User API from your own script.

Desired outcome:

• Pick a cadence (weekly or monthly) and which files to include (contacts, notes, network updates).
• Receive the CSV by email or a download link when it is ready.
• Keep manual exports available as they are today.