The 0xBE prefix byte triggers extended opcode parsing. Reads the
opcode number from the next byte, then parses operand types using
the same format as VAR opcodes. Required for all V5+ games.
Copies the cleaned-up zvm source (ruff-compliant, ty-clean) back into
the zmachine module. Adds __init__.py with proper exports and updates
.gitignore for debug.log/disasm.log.