OnlineBoard search: render Купить/Онлайн регистрация in expanded row

Angular's board search results expansion shows [Купить] [Онлайн
регистрация] [Детали рейса]. React only rendered Details. Added a
`renderActions` prop on FlightCard/FlightList so the feature layer
can inject extra buttons without the ui layer importing from
features. OnlineBoardSearchPage wires it to FlightActions with
showShare=false (the row already has a dedicated share icon).

Visibility rules fall through to canBuyTicket / canRegister (same
as BoardDetailsHeader), so cancelled/past flights still hide the
Buy button and carriers without a registrationUrl still hide the
Online Registration button — matching Angular's per-flight gating.

Integration test mocks useAppSettings to avoid requiring the real
ApiClientProvider in flight-search.test.tsx.

src/ui/flights/FlightCard.tsx

@@ -46,6 +46,13 @@ export interface FlightCardProps {
    * pages to render the per-leg route diagram.
    */
   renderExpandedBody?: (flight: ISimpleFlight) => ReactNode;
+  /**
+   * Extra action buttons rendered before the default share + details
+   * buttons in the expanded actions row. Used by the online-board
+   * search page to surface the same Купить / Онлайн регистрация
+   * buttons Angular shows on the search results expansion.
+   */
+  renderActions?: (flight: ISimpleFlight) => ReactNode;
 }
 
 /** Extract the primary leg from a flight (first leg for multi-leg) */
@@ -116,6 +123,7 @@ export const FlightCard: FC<FlightCardProps> = ({
   onViewDetails,
   direction = "route",
   renderExpandedBody,
+  renderActions,
 }) => {
   const { t } = useTranslation();
   const { language } = useLocale();
@@ -415,6 +423,12 @@ export const FlightCard: FC<FlightCardProps> = ({
               >
                 <img src="/assets/img/share.svg" alt="" aria-hidden="true" />
               </button>
+              {/* Extra actions (Купить / Онлайн регистрация). Angular
+                  renders Buy + Registration + Details here on every
+                  expanded board row; the caller wires up FlightActions
+                  via renderActions so the visibility rules live with
+                  the feature instead of leaking into the ui layer. */}
+              {renderActions?.(flight)}
               <button
                 type="button"
                 className="flight-card__details-btn"

src/ui/flights/FlightList.tsx

@@ -33,6 +33,13 @@ export interface FlightListProps {
    * default time/transition rows.
    */
   renderExpandedBody?: (flight: ISimpleFlight) => ReactNode;
+  /**
+   * Extra action buttons rendered in the default expanded-body actions
+   * row, right before the share/details buttons. Threads down to each
+   * FlightCard for the online-board search page where Angular shows
+   * Купить / Онлайн регистрация alongside Детали рейса.
+   */
+  renderActions?: (flight: ISimpleFlight) => ReactNode;
 }
 
 /**
@@ -49,6 +56,7 @@ export const FlightList: FC<FlightListProps> = ({
   initialCurrentFlightId,
   direction = "route",
   renderExpandedBody,
+  renderActions,
 }) => {
   const { t } = useTranslation();
   const cardRefs = useRef<Map<string, HTMLDivElement>>(new Map());
@@ -102,6 +110,7 @@ export const FlightList: FC<FlightListProps> = ({
               ? { onViewDetails: () => onFlightClick(flight) }
               : {})}
             {...(renderExpandedBody ? { renderExpandedBody } : {})}
+            {...(renderActions ? { renderActions } : {})}
           />
         </div>
       ))}