fix: chat PlayerName fallback + nouveau build WebGL 20260517b

- ChatUI: PlayerName utilise PlayerPrefs comme fallback si non connecte
- NetworkManager: sauvegarde le nom dans PlayerPrefs a la connexion
- GameCanvas: version build bump -> 20260517b (cache bust)
- Nouveaux fichiers build_mai (data + wasm mis a jour)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

game/Assets/Scripts/Network/NetworkManager.cs

@@ -113,6 +113,7 @@ public class NetworkManager : MonoBehaviour
         LastError = "";
         LocalPlayerName = playerName;
         LocalPlayerColor = color;
+        PlayerPrefs.SetString("rolld_player_name", playerName);
 
         try
         {