Giving streak tracking

Recognize donors on consecutive monthly or yearly giving streaks — "5 monthly gifts in a row," "3rd year of giving on Giving Tuesday," "6-month sustainer milestone." Streaks show on donor records, drive automated milestone celebrations, and surface in the AI Stewardship Agent's outreach. Streak data is one of the strongest retention signals in fundraising — donors with 12+ month streaks rarely churn. Make it visible and celebrate it.