[SkyBlade1978]

Grass steps and corners can now be flattened into matching path pieces. Flattening a grass piece also changes ordinary grass beneath it in the same shovel action, and grass/snow fringes remain visible on partial pieces.

Mineralogy's 27 natural rocks get steps and corners automatically when installed. Its native slabs are retained for placement and recombination; the earlier test add-on's saved pieces are recovered. Vertical-pair recipes rebuild corners into steps and steps into slabs, including registered add-on materials.

This prepares 0.3.7.110021. Building Pieces still works alone and generates no terrain. Existing palettes, IDs and schema are preserved, with two appended path palettes and 35 optional Mineralogy palettes.

Migration fixtures that use Terrain Smoother are explicitly opt-in, so ordinary builds and CI do not need another local checkout.

Validation:

• 59 unit tests, development fresh/reload runtime checks, build, Javadocs, Eclipse isolation and artifact audits passed.
• Exact packaged standalone and combined client/server fresh/reload checks passed with released Grass Slabs 1.1.1.110021 and checksum-locked Mineralogy, OreSpawn and Terrain Smoother candidates.
• Packaged fresh/reload checks also passed with public Mineralogy 6.0.1.110021 and OreSpawn 4.1.3.110021 jars, with both download hashes verified.
• Checked 400 shovel interactions, all 540 Mineralogy piece states and 9×9 generation-order comparisons at all three smoothing levels.
• Upgraded a disposable save made with released 0.3.6.110021: 3,374 placed states and 643 stacks containing 10,196 item units retained their identities and custom data. Schema and counters were preserved, with newly visited chunks counted once; reload was stable. The source fixture was unchanged.
• Two local builds produced identical main, sources, Javadocs and checksum files. Main classes target Java 8; no development probes, local paths or agent files are included.

[CLAassistant]

All committers have signed the CLA.