Port OreSpawn 4.0.16 to Forge 1.15.2

[SkyBlade1978]

Summary

Ports the accepted OreSpawn 4.0.16 campaign to Forge 1.15.2, finishing at 4.0.16.115021 while preserving Forge 31.2.57, MCP snapshot 20200514-1.15.1, Java 8 bytecode, pack format 5, API major 1, and schemas 4/6/5.

This retains the already accepted 4.0.8 field-persistence/build work and 4.0.9 natural-host ordering, then adds the applicable 4.0.10-4.0.16 fixes:

• evaluates Stable Layers rock bounds against actual world Y while retaining shifted formation identity;
• aligns public surface sampling with highest-occupied terrain;
• adds immutable Ore-dimension biome ID and dictionary filter builder/getter contracts through the existing provider fields;
• accepts canonical namespaced and legacy unnamespaced geome IDs;
• converts exposed one-layer Snow at top + 1 while preserving buried/authored Snow and Ice;
• shares Forge 1.15's direct 3D noise-biome lookup across generation and public sampling, including vertical biome boundaries;
• gives explicit stable biome IDs precedence over object aliases and keeps hot generation paths allocation-free;
• makes family-restricted ores use the selected dimension's geome configuration rather than the global Overworld configuration.

Forge 1.15 has a static biome registry, so the 4.0.11 dynamic-registry lifecycle change is intentionally inapplicable. It also has no server GameTest harness, so 4.0.16 records the shared release identity while retaining ordinary dedicated benchmark auto-stop.

Target-specific build and compatibility work

• preserves ForgeGradle 7.0.34, Gradle 9.6.1 and Forge 31 reobfuscation;
• runs Gradle with Java 17 and compiles all production/test/fixture code with the exact Java 8 toolchain;
• qualifies the Forge 31 cold bootstrap with Java 25 available to Mavenizer, with no source-compatibility patch required;
• retains the five target access-transformer rules, native matrix-free screens, direct screen navigation, translated captions and duplicated Eclipse bin/main discovery contract;
• keeps API/schema/provider/profile/migration semantics and existing chunks unchanged;
• keeps dependency compatibility at [4.0.6,5.0.0).

Validation

The exact manually accepted head is 6a6276f786e7b005a1f59d314724a7e97127e857.

• 130 tests across 35 suites; zero failures, errors or skips;
• 26 JSON/mcmeta files independently parsed;
• exact parity across 16 locales with 357 keys each;
• byte parity across all 21 exported documents;
• full offline build, Javadocs, release audit/checksums and Eclipse launch/classpath verification;
• repeated cold exact-commit lifecycle plus genuine empty-cache online bootstrap and same-cache offline replay;
• exact reobfuscated Forge 31 packaged client/server fresh and reload tests;
• long editor-field round trip, surface/natural-host/weather/biome-family/ore/fluid/migration qualification and clean runtime-log scans;
• preferred-seed fresh/reload verification with stable profile hash and unchanged earlier chunks;
• three matched Sky/Average benchmark repetitions with Cyano and vanilla controls; control-normalized overhead was 8.832%, below the 10% investigation threshold;
• all three release jars audited for Java class major 52, metadata, reobfuscation, access transformers, docs/locales and zero fixture/oracle/test/world leakage.

This PR does not tag or publish a release and does not directly modify the MMD target branch.