feat(p2p): add Phase 4 merchant tier system and migrations

- Add merchant tier system (Lite/Super/Diamond) with tier badges
- Add advanced order filters (token, fiat, payment method, amount range)
- Add merchant dashboard with stats, ads management, tier upgrade
- Add fraud prevention system with risk scoring and trade limits
- Rename migrations to timestamp format for Supabase CLI compatibility
- Add new migrations: phase2_phase3_tables, fraud_prevention, merchant_system

web/supabase/.gitignore

@@ -0,0 +1,8 @@
+# Supabase
+.branches
+.temp
+
+# dotenvx
+.env.keys
+.env.local
+.env.*.local