Sponsored campaigns (cross-promo)

From Campaigns (/lumyly-campaign):

1. Pick a biolink to promote.
2. Choose Cross-promotion placement.
3. Set an impression budget (minimum 10). Credits are calculated automatically.
4. Optionally enable auto-renew with a cycle limit or unlimited renewals.

States include active, paused, budget exhausted, completed, and cancelled (unused credits are returned per policy). Pause/resume anytime while active.