Tidy the 1.18 build scripts

[SkyBlade1978]

This makes the 1.18 build easier to follow without changing how it works.

The large build.gradle is split into focused files for dependencies, release artifacts, publishing, verification, packaged runtimes, and Eclipse. The old MDK example comments are removed, the remaining comments explain Base Metals-specific decisions, and a short guide describes the new layout.

It also makes Gradle and Markdown line endings explicitly LF.

Checked with:

• the full build, test, data, release audit, and Eclipse isolation tasks
• all 32 GameTests
• a second clean release build
• byte-for-byte comparison of the main, sources, Javadocs, and checksum files with the pre-refactor build