Fix JaCoCo coverage not reaching SonarCloud

Surefire's hardcoded <argLine> block was replacing the ${argLine}
property entirely, so JaCoCo's prepare-agent javaagent flag was
discarded and jacoco.exec stayed empty. Prepend @{argLine} (late-
binding syntax, evaluated after prepare-agent sets it) so both the
JaCoCo agent and the --add-opens flags are active at test time.

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

Author: tastybento

pom.xml

@@ -268,6 +268,7 @@
                         <include>**/*Test??.java</include>
                     </includes>
                     <argLine>
+                        @{argLine}
                         --add-opens java.base/java.lang=ALL-UNNAMED
                         --add-opens java.base/java.math=ALL-UNNAMED
                         --add-opens java.base/java.io=ALL-UNNAMED