Wire Jacoco agent into surefire argLine

Surefire's <argLine> was hard-coded with the --add-opens flags only,
which overrode the ${argLine} property that
jacoco-maven-plugin:prepare-agent sets to attach the coverage agent.
As a result no jacoco.exec was ever produced and SonarCloud reported
0% coverage despite the suite running. Prepending @{argLine} lets
Maven late-bind the Jacoco-supplied javaagent flag alongside the
existing --add-opens, so coverage now lands in
target/site/jacoco/jacoco.xml where the Sonar scanner picks it up.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: tastybento

pom.xml

@@ -248,6 +248,7 @@
                         <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