fix: test migration cleanup for discount types/tables, fix type ordering in init-script

- Add new discount types to testdb.Migrate drop list (campaign_type, milestone_type, etc.)
- Add new discount tables to testdb.Migrate drop order and TruncateTables
- Move discount type definitions to top of init-script.sql with other enums
- Remove duplicate type definitions that were after admin_notification_reason
- Types must be defined before tables that reference them

backend/testutils/testdb/testdb.go

@@ -77,6 +77,11 @@ func Migrate(t *testing.T, pool *pgxpool.Pool) {
 			"DROP TYPE IF EXISTS booking_status CASCADE",
 			"DROP TYPE IF EXISTS verification_purpose CASCADE",
 			"DROP TYPE IF EXISTS admin_notification_reason CASCADE",
+			"DROP TYPE IF EXISTS campaign_type CASCADE",
+			"DROP TYPE IF EXISTS milestone_type CASCADE",
+			"DROP TYPE IF EXISTS milestone_unit CASCADE",
+			"DROP TYPE IF EXISTS discount_campaign_scope CASCADE",
+			"DROP TYPE IF EXISTS discount_campaign_status CASCADE",
 		}
 		for _, stmt := range typeDrops {
 			if _, err := pool.Exec(ctx, stmt); err != nil {
@@ -86,6 +91,9 @@ func Migrate(t *testing.T, pool *pgxpool.Pool) {
 		
 		// Drop all tables, sequences, and views in correct order
 		dropOrder := []string{
+			"booking_discounts",
+			"loyalty_redemptions",
+			"discount_campaigns",
 			"forgiven_no_shows",
 			"admin_notifications",
 			"user_notification_preferences",
@@ -187,6 +195,9 @@ func TruncateTables(t *testing.T, pool *pgxpool.Pool) {
 	ctx := context.Background()
 
     tables := []string{
+        "booking_discounts",
+        "loyalty_redemptions",
+        "discount_campaigns",
         "forgiven_no_shows",
         "user_social_logins",
         "verification_codes",