feat: add gateway billing estimate and rate limit details

apps/api/internal/store/user_group_policy.go

@@ -10,6 +10,7 @@ import (
 type UserGroupPolicy struct {
 	ID                    string
 	GroupKey              string
+	Name                  string
 	RateLimitPolicy       map[string]any
 	BillingDiscountPolicy map[string]any
 }
@@ -23,12 +24,12 @@ func (s *Store) ResolveUserGroupPolicy(ctx context.Context, user *auth.User) (Us
 	var rateLimit []byte
 	var billing []byte
 	err := s.pool.QueryRow(ctx, `
-SELECT id::text, group_key, rate_limit_policy, billing_discount_policy
+SELECT id::text, group_key, name, rate_limit_policy, billing_discount_policy
 FROM gateway_user_groups
 WHERE status = 'active'
   AND (($1 <> '' AND id = NULLIF($1, '')::uuid) OR ($1 = '' AND group_key = 'default'))
 ORDER BY CASE WHEN id::text = $1 THEN 0 ELSE 1 END, priority ASC
-LIMIT 1`, userGroupID).Scan(&item.ID, &item.GroupKey, &rateLimit, &billing)
+LIMIT 1`, userGroupID).Scan(&item.ID, &item.GroupKey, &item.Name, &rateLimit, &billing)
 	if err != nil {
 		if err == pgx.ErrNoRows {
 			return UserGroupPolicy{}, nil