Add ore overlays and finish the 1.13 configuration and recipe fixes

[SkyBlade1978]

What changes

This brings the remaining 1.13.2 work into master-1.13.2.

• Use Kiri's transparent ore overlays over vanilla Stone, Netherrack and End Stone textures. Resource packs can now replace the surrounding rock without leaving the ores behind. His original texture commit and author credit are preserved.
• Generate ore models automatically during builds and Eclipse Gradle refreshes, while keeping CI checks for stale generated files.
• Open the same configuration screen from the Mods list and the OreSpawn cog. Add High Fantasy and Low Fantasy, with translated labels and help in all 18 languages.
• Keep old configurations on High Fantasy by default. Check client/server modes during login, without tying the setting to individual worlds or removing registered items.
• Match 1.12 recipe discovery: finding an ingot reveals that metal's crafting recipes. Keep existing advancement progress and restore earned unlocks when returning from Low Fantasy to High Fantasy.
• Improve player-facing tooltips and documentation, fix Gradle client launches, and allow newer Java 8 updates for development. Release builds still use the pinned compiler.
• Keep permanent upgrade and runtime tests separate from the public JAR. No agent notes, generated worlds or test logs are included.

Ore placement still uses the published OreSpawn 4.1.0.113021 release. The eleven ore rules, registry IDs and existing item behaviour are unchanged.

Checks

• Clean build, 58 unit tests, generated-data checks, Javadocs, dependency checks and release-JAR auditing.
• Eclipse launch generation and production-classpath isolation.
• Packaged Forge client and dedicated-server tests with the exact OreSpawn release: both config entry points, all 13 ore overlays, resource-pack host replacements and 28,147 runtime assertions.
• Ten multiplayer scenarios covering unchanged old configs, missing configs, both modes, intentional mismatch messages, reloads and recipe unlock restoration.
• Separate Cyano 1.10, MMD 1.10 and MMD 1.12 upgrade fixtures: first load and reload passed with no block or item mismatches. Original source worlds stayed unchanged.
• Two clean builds produced identical main, sources and Javadoc JARs and checksum files.

The README and changelog describe the settings, migration steps and build requirements. This PR does not publish a release or create a tag.