fix: use h-dvh instead of h-screen on mobile draft board (#31)

Replace h-screen (100vh) with h-dvh (100dvh) on the root draft room
container. On mobile browsers, 100vh equals the max viewport height
when the address bar is hidden, causing the page to overflow when the
address bar is visible. 100dvh (dynamic viewport height) correctly
adjusts to the actual visible area at all times.

https://claude.ai/code/session_01GecUeTHw4Mc2ErSYJ6WXae

Co-authored-by: Claude <noreply@anthropic.com>

app/routes/leagues/$leagueId.draft.$seasonId.tsx

@@ -1092,7 +1092,7 @@ export default function DraftRoom() {
     : null;
 
   return (
-    <div className="h-screen bg-background flex flex-col overflow-hidden">
+    <div className="h-dvh bg-background flex flex-col overflow-hidden">
       {/* Draft Completion Banner */}
       {isDraftComplete && (
         <div className="bg-emerald-500/20 border-b border-emerald-500/30 text-emerald-400 px-4 py-3 text-center font-semibold flex-shrink-0">