Pulsar Lighting Engine

Changed

• Update Gradle to 9.9.0 and actions/setup-java to v6.2.0.
• Publish beta-tagged builds as beta files on CurseForge and Modrinth while keeping the GitHub Release's pre-release flag disabled.
• Use the matching CHANGELOG entry as the release notes on all distribution sites.

Fixed

• Block light crossing the sealed horizontal boundary between adjacent upper and lower opaque slabs in SCALAR and RGB lighting (issue #29).
• Avoid dark bands on exposed wall faces next to slabs by sampling their visible cavity instead of the opaque wall's interior at covered vertices (issue #29).
• Rebuild older saved lighting with cache version 15 to remove leaked slab light.