fix(maven): propagate batch runner exit code failures

The batch executor was always resolving the promise even when the
batch runner JAR exited with a non-zero code. This meant that test
failures were not being propagated back to the CLI.

Now properly rejects the promise when exitCode !== 0, ensuring that:
- Failed tests cause the nx command to throw an error
- The test output is captured and displayed
- The overall command exits with the correct exit code

Author: FrozenPandaz

packages/maven/src/executors/maven/maven-batch.impl.ts

@@ -197,7 +197,12 @@ export default async function* mavenBatchExecutor(
           console.error(output);
         }
       }
-      resolve();
+      // Reject promise if batch runner exited with non-zero code
+      if (code !== 0) {
+        reject(new Error(`Maven batch runner exited with code ${code}`));
+      } else {
+        resolve();
+      }
     });
     child.on('error', reject);
   });