Backport Phase 3 release to Forge 1.16.5

[SkyBlade1978]

Summary

• complete the Forge 1.16.5 Phase 3 lighting backport while preserving existing registry and saved-world identities
• apply the proven 1.14/1.15 recipe-book, advancement, thrown-lamp rendering, obsidian-item, wall-sconce, and optional-integration fixes using 1.16 APIs
• add an idempotent upgrade bridge for supported 1.10.2 and 1.12.2 furniture, including multicolour padded benches and the 1.12 Oh The Biomes add-on namespace
• retain optional Biomes O' Plenty, Oh The Biomes You'll Go, and Immersive Engineering support without absent-mod startup noise
• update the README, changelog, version documentation, CI toolchains, and Eclipse metadata for the 1.16 release

Verification

• clean/check/build/Javadoc and all catalog, JSON, metadata, namespace, repository, workflow, Maven, artifact, and checksum gates
• deterministic main, sources, and Javadoc jars across two builds
• generated Eclipse runs and production-classpath verification
• packaged dedicated-server probe with BOP, BYG, and Immersive Engineering together
• direct disposable 1.12 Phase 2 world upgrade, followed by a second load proving migration idempotence
• automated coverage for all sixteen padded-bench colours, legacy registry translations, retired-BYG fallbacks, nested items, and exact recipe advancement criteria