Preserve legacy Mineralogy upgrades on Forge 1.16.5

[SkyBlade1978]

Preserves existing Mineralogy worlds when updating to OreSpawn 4.0.6 on Forge 1.16.5.

• Recognizes saved Mineralogy 1.10, 1.12 and exact 1.16.5/5.2.0 world lineages, including valid level.dat_old metadata.
• Preserves the Cyano engine, settings and exact rock order for generated legacy worlds; existing OreSpawn world profiles win and stale files do not reclassify fresh worlds.
• Writes atomic, idempotent upgrade reports while preserving source configs, existing chunks and any developer checkout config.
• Adds strict runtime-log scanning and a target-native flowing-water fresh/reload gate (101 covered blocks, stable on reload) without changing production fluid writes.

Validation: 110 tests across 28 suites; fresh/reload surface, biome, geology and dynamic-fluid server gate; 27 structured files; 16 locales with 357 keys; Java 8 clean build, Javadocs, ForgeGradle 5 Eclipse generation and artifact isolation all pass.

No version, API, schema, registry or provider-format change. Ready for review; the remaining gate is a quick player/UI test before merge.