Enable Javadoc doclint errors

[8Keep]

Summary

• fail Javadoc tasks on doclint errors by removing the global doclint suppression and failOnError override
• remove module-local doclint suppressions for terrain, lwjgl3, and saferallocator
• fix the doclint errors exposed in core Javadocs and exclude generated libjglios native-image glue from iOS examples Javadocs

[github-actions]

🖼️ Screenshot tests have failed.

The purpose of these tests is to ensure that changes introduced in this PR don't break visual features. They are visual unit tests.

📄 Where to find the report:

• Direct Download: screenshot-test-report
• Alternatively, go to the failed run summary > Artifacts > screenshot-test-report
• Download the zip and open jme3-screenshot-tests/build/reports/ScreenshotDiffReport.html

⚠️ If you didn't expect to change anything visual:
Fix your changes so the screenshot tests pass.

✅ If you did mean to change things:
Review the replacement images in jme3-screenshot-tests/build/changed-images to make sure they really are improvements and then replace and commit the replacement images at jme3-screenshot-tests/src/test/resources.

✨ If you are creating entirely new tests:
Find the new images in jme3-screenshot-tests/build/changed-images and commit the new images at jme3-screenshot-tests/src/test/resources.

Note; it is very important that the committed reference images are created on the build pipeline, locally created images are not reliable. Similarly tests will fail locally but you can look at the report to check they are "visually similar".

See https://github.com/jMonkeyEngine/jmonkeyengine/blob/master/jme3-screenshot-tests/README.md for more information

Contact @richardTingle (aka richtea) for guidance if required

[gemini-code-assist]

Code Review

This pull request focuses on improving Javadoc quality and consistency across the project. Key changes include fixing malformed HTML tags, updating parameter descriptions to match method signatures, and removing Javadoc error suppression in Gradle build files to enforce stricter documentation standards. A review comment identifies a grammatical improvement in BlendSpace.java, suggesting the use of "between" instead of "among" when referring to exactly two actions.

[8Keep]

Rebased + now ready for review

[8Keep]

This one should be good @riccardobl but I believe there's an issue with the build recently with your ios changes

[riccardobl]

Thanks!

[riccardobl]

Reverted this for now, because it was causing the build to fail due to javadoc errors https://github.com/jMonkeyEngine/jmonkeyengine/actions/runs/26560877797/job/78243326387

Feel free to open a new pr for this.
Would it be possible to make the doclint errors enable only when passing a -PenableJavadocError flag, and then make a dedicated CI task to check the doc, that fails with a notice without stopping the build? It would be less frustrating for contributors i think.