Restore and validate FAWE integration

[minoneer]

Summary

The repository still contains a dedicated uSkyBlock-FAWE module and the docs still present FAWE as an optional way to speed up island generation, but the integration needs to be verified and restored as a supported path on current server/plugin versions.

Current state

• uSkyBlock-FAWE is still part of the multi-module build and shaded into the final plugin
• there is a dedicated FAWEAdaptor
• the docs mention FAWE as an optional dependency for faster generation

Problem

As long as this path is not verified and intentionally maintained, it sits in an awkward state:

• users may assume it is fully supported
• code can silently drift against current FAWE/WorldEdit APIs
• release and support expectations stay unclear

Goal

Either restore FAWE integration as a tested supported option on current versions, or narrow and document the supported behavior clearly.

Done when

• the expected FAWE + WorldEdit version range is known
• island generation/regeneration works correctly with that stack
• docs/setup guidance match reality
• unsupported paths are removed or clearly documented