Add map-specific tournament creation link

app/tournaments/page.tsx

@@ -2,13 +2,20 @@ import { Header, Footer } from "@/components/Shell";
 import { TournamentIndex } from "@/components/TournamentLobby";
 import { user } from "@/lib/supabase";
 
-export default async function TournamentsPage() {
+export default async function TournamentsPage({
+  searchParams,
+}: {
+  searchParams: Promise<{ map?: string | string[] }>;
+}) {
   const account = await user();
+  const { map } = await searchParams;
+  const initialMapId =
+    typeof map === "string" && /^[0-9a-f-]{36}$/i.test(map) ? map : null;
   return (
     <>
       <Header />
       <main id="main-content">
-        <TournamentIndex signedIn={!!account} />
+        <TournamentIndex signedIn={!!account} initialMapId={initialMapId} />
       </main>
       <Footer />
     </>