feat: Implement client-side game logic and UI with WebSocket message handlers, including a winner popup and confetti animation.

src/server-deno/public/js/ui.js

@@ -105,10 +105,19 @@ export function wireUi() {
     });
   }
 
+  // Auto-uppercase room code input for better UX
+  if ($roomCode) {
+    wire($roomCode, "input", () => {
+      const pos = $roomCode.selectionStart;
+      $roomCode.value = $roomCode.value.toUpperCase();
+      $roomCode.setSelectionRange(pos, pos);
+    });
+  }
+
   wire($createRoom, "click", () => sendMsg({ type: "create_room" }));
 
   wire($joinRoom, "click", () => {
-    const code = $roomCode.value.trim();
+    const code = $roomCode.value.trim().toUpperCase();
     if (code) sendMsg({ type: "join_room", roomId: code });
   });