feat(biome): implement foliage colormap tinting for oak leaves and vegetation

[BharathASL]

Description

Implement Minecraft Java foliage colormap tinting for oak leaves and vegetation blocks. Extends the biome UI predicate with getBlockTintCategory and shouldApplyFoliageTint to detect foliage blocks across all 6 cuboid faces while preserving backwards-compatible grass tinting for grass blocks. In getMaterialsForBlock and cross-quad vegetation rendering, foliage blocks now sample authentic colormap colors from foliage.png (or hardcoded overrides for Swamp and Badlands) and apply uniform biome tinting across all faces.

Related Issues

Closes #50

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation / Hygiene update

Checklist

• My code follows the style of the surrounding code.
• I have run this repository's tests locally and they pass.
• I have added tests that prove my fix is effective or that my feature works.
• I have updated documentation / CHANGELOG as appropriate.
• My commits follow Conventional Commits.
• Every commit is signed off (git commit -s), per section 5 of CONTRIBUTING.md.

[ninja6-agent]

No issues found.