Modernize Mineralogy 1.12 CI/CD and README

[SkyBlade1978]

Summary

• generalize the multi-target release dispatcher and read-only tag validation for the maintained branches
• pin the build, wrapper-validation, and CodeQL workflows to immutable Action revisions
• force CodeQL to perform an uncached production compilation so Java analysis always receives a compiler trace
• stage and SHA-256 verify released OreSpawn 4.0.7.112021 (CurseForge file 8685379) in CI, avoiding clean-runner CurseMaven throttling without changing the declared dependency
• restore the public project and branch-specific build badges in the README

Runtime and release scope

This is CI/CD, build-verification, test-contract, and README maintenance only. It does not change src/main, gameplay, world generation, recipes, registries, assets, configuration behavior, provider schemas, the changelog, or the published version 6.0.1.112021.

No new Mineralogy release is requested or required for these changes.

Validation

The exact fork head is f3c1b66b69442b05bbd7fe4eda59c42b276170ae.

• Build, test, and audit passed on the fork
• Gradle wrapper Validation passed
• CodeQL Analyze Java passed
• the PR-facing diff contains no production source/resource or changelog changes
• the MMD PR Port Minecraft 1.12.2 to Mineralogy 6.0.1 and OreSpawn 4 #137 merge tree is identical to the accepted fork base, so this PR contains only the three intended maintenance commits