Add host and player identification in GamePickerCard

This update introduces visual indicators to identify the host and the current user in the GamePickerCard component. Hosts are marked with a star, and the current user is labeled as "(du)". The design of the member pills has also been enhanced for better clarity and aesthetics.

frontend/src/App.jsx

@@ -515,6 +515,8 @@ export default function App() {
           setGameId={setGameId}
           onOpenHelp={() => setHelpOpen(true)}
           members={members}
+          me={me}
+          hostUserId={gameMeta?.host_user_id || ""}
         />
 
         {/* Sieger Badge: zwischen Spiel und Verdächtigte Person */}