ci: add conditional check and verbose logging for coveralls step

- Only run coverallsJacoco if COVERALLS_REPO_TOKEN is set
- Add --info flag for detailed logging to diagnose issues

Assisted-By: Claude Code

Author: sonus21

.github/workflows/java-ci.yaml

@@ -465,6 +465,7 @@ jobs:
           if-no-files-found: ignore
 
       - name: Push coverage to Coveralls
+        if: ${{ secrets.COVERALLS_REPO_TOKEN != '' }}
         env:
           COVERALLS_REPO_TOKEN: ${{ secrets.COVERALLS_REPO_TOKEN }}
-        run: ./gradlew coverallsJacoco
+        run: ./gradlew coverallsJacoco --info