Add Maven plugin inspections to CI

[jormundur00]

Issue

Resolves #909.

Spec Fit

This keeps the existing Maven plugin workflow ownership boundary and path filters, and adds the missing Maven plugin inspection evidence requested by the issue. The grounded CI architecture spec and Maven plugin E2E CI coverage docs were updated so test-native-maven-plugin.yml now documents Maven functional tests, Maven plugin inspections, and GraalVM dev-build functional tests.

Implementation

• Added an inspect-native-maven-plugin job to .github/workflows/test-native-maven-plugin.yml.
• The job checks out the repository, runs the existing prepare-environment action with Java 17.0.12, skips the separate GraalVM test JDK, and runs ./gradlew :native-maven-plugin:inspections.
• Updated the workflow summary comment plus the grounded CI architecture and Maven E2E docs.

Validation

• git diff --check
• grund check
• grund fmt . --marker --check
• JAVA_HOME=/home/jovan/.sdkman/candidates/java/17.0.12-graal PATH=/home/jovan/.sdkman/candidates/java/17.0.12-graal/bin:$PATH ./gradlew :native-maven-plugin:inspections --no-daemon

Local actionlint validation was not run because actionlint is not installed locally. The repository's Macaron GitHub Actions policy workflow remains the CI-side workflow/action gate for this change.

Review Readiness

Review artifact review-2.md reports no blocking findings, no non-blocking follow-ups, acceptable validation gaps, and Ready to publish: yes.

Human Follow-up

• Maintainers should review the draft PR and wait for repository CI, including the Macaron workflow policy gate.
• No reviewer was requested automatically.