Add explicit heap configuration for tests

This ensures consistent test behavior across platforms, particularly
on macOS CI runners where default heap sizing may differ. The tests
require approximately 1GB of heap space to run successfully.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: oschwald

pom.xml

@@ -248,6 +248,9 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>3.5.4</version>
+                <configuration>
+                    <argLine>-Xmx1024m</argLine>
+                </configuration>
             </plugin>
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>