Testing revealed that custom Huffman trees from our treegen cause the
original UC2 Pro to hang even for single-file archives. The original's
ASM decompressor kernel (nuke1) has undocumented assumptions about tree
shapes that our treegen doesn't match.
Default tree is the only working option for backward compatibility.
Multi-file extraction remains a separate open issue (hangs even with
default tree, while listing works).
c731bd75c2