Migrate service build and codebase baseline to Java 25

[Copilot]

This PR migrates the project from Java 11 to Java 25 and applies compatible code/build modernizations so the service targets the new runtime level consistently across Maven and CI.

• Build target + toolchain

  • Updated Maven Java target from 11 → 25 (maven.compiler.release, compiler plugin release).
  • Upgraded Java-sensitive Maven plugins to Java 25–compatible versions (compiler/surefire/failsafe).
  • Added JVM --add-opens args for surefire/failsafe to preserve test/runtime compatibility under newer JDK encapsulation.

• CI runtime alignment

  • Updated GitHub Actions Java setup from JDK 11 → JDK 25 so CI executes with the same target runtime.

• Source-level Java modernization

  • Applied recipe-driven language upgrades in touched classes:
    • pattern matching for instanceof
    • switch expression conversion
    • unnamed catch parameter usage
    • instance main signature migration where applicable

• Migration note / blocker visibility

  • Local build failure after migration is error: release version 25 not supported, consistent with local runner using Java 17 instead of Java 25.

<!-- pom.xml -->
<properties>
  <maven.compiler.release>25</maven.compiler.release>
</properties>
...
<plugin>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>3.15.0</version>
  <configuration>
    <release>25</release>
  </configuration>
</plugin>

This change was produced with Moderne CLI and Moderne Agent Tools (MCP).