Fix global RPC data parsing in BackendService

- Resolved massive bug where api_rpc_async returned raw payload strings instead of the parsed 'data' Dictionary expected by every system (Gacha, Mail, Leaderboard, Admin Panel, etc.)
- Restored Admin Panel's _rpc helper to use the standard result.get('data') format now that BackendService correctly supplies it.

scripts/services/backend_service.gd

@@ -121,9 +121,18 @@ func api_rpc_async(rpc_id: String, payload: String = "{}") -> Dictionary:
 			}
 		
 		# Success
+		var payload_str: String = result.payload if result.payload != null else "{}"
+		if payload_str.is_empty():
+			payload_str = "{}"
+		
+		var parsed_data = JSON.parse_string(payload_str)
+		if parsed_data == null:
+			parsed_data = {}
+			
 		return {
 			"success": true,
-			"payload": result.payload
+			"payload": payload_str,
+			"data": parsed_data
 		}
 		
 	return { "success": false, "error": ErrorCode.NETWORK_ERROR, "message": "Max retries exceeded" }

scripts/ui/admin_panel.gd

@@ -301,15 +301,7 @@ func _rpc(rpc_name: String, payload: Dictionary) -> Dictionary:
 		var err: String = str(result.get("message", "Unknown error"))
 		_set_status(err, CLR_STATUS_ERR)
 		return {"error": err}
-	
+	return result.get("data", {})
-	var payload_str: String = result.get("payload", "{}")
-	if payload_str.is_empty():
-		payload_str = "{}"
-		
-	var parsed = JSON.parse_string(payload_str)
-	if typeof(parsed) == TYPE_DICTIONARY:
-		return parsed
-	return {}
 
 func _set_status(msg: String, color: Color = CLR_DIM) -> void:
 	status_label.text = msg