Add Affiliate Tracking to Lovable App

Add an affiliate/referral tracking system to my Lovable app.

REQUIREMENTS:
1. Generate unique referral links for each affiliate (e.g., yoursite.com?ref=ABC123). Store the referral code in a cookie lasting 30 days.
2. Create an affiliate signup form for new affiliates: name, email, website, payment method (PayPal email). Save to a Supabase "affiliates" table.
3. Track clicks: when a user visits with a ref parameter, log the click in a "referral_clicks" table with timestamp, IP (hashed), and user agent.
4. Track conversions: when a referred user completes a purchase or signup, log it in a "referral_conversions" table linked to the affiliate.
5. Create an affiliate dashboard showing: total clicks, conversions, conversion rate, earnings, and payout history.
6. Support configurable commission rates (flat fee or percentage) stored in the affiliates table.
7. Admin panel for managing affiliates: approve/reject applications, view performance, process payouts.

DATABASE:
- "affiliates" table: id, user_id, name, email, website, referral_code (unique), commission_type, commission_rate, status (pending/active/suspended), payout_email, created_at
- "referral_clicks" table: id, affiliate_id, ip_hash, user_agent, page_url, created_at
- "referral_conversions" table: id, affiliate_id, order_id, amount, commission_earned, status (pending/paid), created_at
- RLS: Affiliates see only their own data. Admins see all.

ENVIRONMENT VARIABLES:
- COOKIE_DOMAIN (for referral cookie)

SECURITY:
- Hash IP addresses — never store raw IPs.
- Validate referral codes server-side.
- Prevent self-referrals by checking affiliate email against buyer email.