fixes

apps/api/internal/httpapi/stripe_handlers.go

@@ -45,6 +45,15 @@ func (s *Server) handleStripeCheckout(w http.ResponseWriter, r *http.Request) {
 		Error(w, http.StatusForbidden, "admin required")
 		return
 	}
+	platformAdmin, err := s.checkPlatformAdmin(r.Context(), uid)
+	if err != nil {
+		LogAndError(w, http.StatusInternalServerError, "failed to verify platform admin", err)
+		return
+	}
+	if err := s.stripeSvc().EnsureSelfServeCheckout(r.Context(), platformAdmin); err != nil {
+		ClientOrLog(w, http.StatusServiceUnavailable, "checkout unavailable", err, billing.ClientError)
+		return
+	}
 	var body billing.CheckoutRequest
 	if err := DecodeJSON(r, &body); err != nil {
 		Error(w, http.StatusBadRequest, "invalid json")