Referral program for a SaaS

Build a referral program that any SaaS can bolt on.

Core features:
1. Each user gets a unique referral link
2. New signups via that link get credited to the referrer
3. Referrer earns credit / cash after referred user hits milestone
4. Referrer dashboard: clicks, signups, rewards, payout method

Data: referral_codes, referral_events, rewards.
Must-haves: fraud checks (same IP, same email domain), Stripe Connect payouts.