fix: ensure proper handling of null scaling mode and standardize scaling mode case conversion

Author: FllipEis

api/src/main/java/app/simplecloud/api/internal/group/GroupApiImpl.java

@@ -10,6 +10,7 @@
 
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 
@@ -273,7 +274,7 @@ private ModelsScalingConfig convertScalingConfig(ScalingConfig config) {
         result.setMinServers(config.getMinServers());
         result.setPlayerThreshold(java.math.BigDecimal.valueOf(config.getPlayerThreshold()));
         if (config.getScalingMode() != null) {
-            result.setScalingMode(config.getScalingMode().name());
+            result.setScalingMode(ModelsScalingMode.valueOf(config.getScalingMode().name().toUpperCase(Locale.ROOT)));
         }
 
         if (config.getScaleDown() != null) {

api/src/main/java/app/simplecloud/api/internal/group/GroupImpl.java

@@ -267,7 +267,8 @@ private ScalingConfig convertScalingConfig(app.simplecloud.api.web.models.Models
         result.setMaxServers(config.getMaxServers() != null ? config.getMaxServers() : 0);
         result.setMinServers(config.getMinServers() != null ? config.getMinServers() : 0);
         result.setPlayerThreshold(config.getPlayerThreshold() != null ? config.getPlayerThreshold().doubleValue() : 0.0);
-        String scalingModeStr = config.getScalingMode();
+        assert config.getScalingMode() != null;
+        String scalingModeStr = config.getScalingMode().toString();
         if (scalingModeStr != null) {
             try {
                 result.setScalingMode(ScalingMode.valueOf(scalingModeStr));