Refactor WorldManager to reliably extract map archives and harden extraction.
- Add documentation and ARCHIVE_ROOT constant for expected archive layout (must contain a leading "world/" folder).
- Fix archive type detection (use file.name) and ensure target world folder exists before extraction.
- Implement unzip and untar that strip the leading "world/" prefix, skip the bare root entry, and log unexpected entries.
- Add Zip Slip guards for both ZIP and TAR extraction to prevent path traversal.
- Use buffered input for tar.gz performance and correct tar entry iteration.
- Add extractAsync helper to run I/O off the main thread and invoke a completion callback on the main thread (for potential onEnable migration).
- Improve logging and error messages.
c261a3a07c