Fix relief rendering on Minecraft 1.17.1

[SkyBlade1978]

Summary

• fix Mineralogy relief rendering so the intentionally open centre shows the supporting block face instead of sky/void
• bump the Minecraft 1.17.1 release identity from 6.1.0.117011 to 6.1.1.117011
• update release checks, CI artifact names, README, changelog, version guide, and regression contracts

Cause and fix

RockRelief already returned an empty visual shape, but its thin full-face shape remained the occlusion shape. Minecraft 1.17 therefore culled the supporting block face behind the open model centre. The block now also returns Shapes.empty() from getOcclusionShape.

This changes no registry IDs, NBT, recipes, world generation, OreSpawn integration, or existing-world identities.

Validation

• manually verified in Minecraft 1.17.1 that reliefs now render correctly
• 50 JUnit tests pass
• clean check build javadoc verifyReleaseConfiguration verifyReleaseDependencies verifyReleaseArtifacts writeReleaseChecksums
• genEclipseRuns eclipse isolateEclipseProductionRuns verifyEclipseProductionClasspath
• git diff --check
• candidate main-jar SHA-256: 4AB24679C9F996F32E8E58398065A8D2681A90C27241510F067E4045014F9B1E

No tag or publication is included in this PR.