chore: enable PMD PreserveStackTrace rule

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

Author: joaodinissf

ddk-configuration/pmd/ruleset.xml

@@ -84,7 +84,6 @@
     <exclude name="UnitTestShouldUseBeforeAnnotation"/><!--Checkstyle-->
     <exclude name="UnitTestShouldUseTestAnnotation"/>
     <exclude name="NonExhaustiveSwitch"/>
-    <exclude name="PreserveStackTrace"/><!--TODO-->
     <exclude name="UnnecessaryWarningSuppression"/> <!--Experimental, too many false positives-->
     <exclude name="UnusedLocalVariable"/><!--Checkstyle-->
     <exclude name="UseTryWithResources"/><!--TODO-->