Migrate PowerAdvantage 1.12.2 to ForgeGradle 7

[SkyBlade1978]

Summary

• migrate the Minecraft 1.12.2 build to ForgeGradle 7.0.34 and Gradle 9.6.1 while retaining Java 8 bytecode compatibility
• restore conduit networks and powered-machine GUI state correctly after full world reloads
• keep optional RF and RebornCore integrations compile-only, with conditional transformer registration and complete model coverage
• add reproducible release artifacts, dependency and identity audits, checksums, Eclipse launch isolation, CI, CodeQL, wrapper validation, and guarded tag validation

Compatibility

• retains the poweradvantage mod ID, registry names, tile IDs, assets, configuration names, fluid names, recipes, NBT keys, and legacy API packages
• retains BaseMetals and OreSpawn as CurseForge requirements without adding them to the compile or development runtime classpaths
• release version is 2.4.1.112021

Validation

• clean check build javadoc verifyReleaseDependencies verifyReleaseArtifacts writeReleaseChecksums verifyEclipseProductionClasspath
• 27 Gradle tasks passed
• exact generated Eclipse client launch reached the main menu with all 11 test mods loaded
• manual Eclipse client startup confirmed
• release JAR SHA-256: 45F0FA337A517B756CC257235FF18E6180347302A6D27813E6B80150F367B5C2