asset-extraction

Write tools/extract_assets.py - the single-file uv run script with inline PEP 723 dependencies that reads the user's own copy of the software and writes exactly what the rebuilt program needs into data/ - and reverse-engineer the archive and asset formats it needs (pak/wad/bigfile/disc filesystems, compression, textures, audio), proving them with a round trip. Use when the reconstruction needs the original's assets, when an archive format must be decoded, or when the user asks how to get their game data into the rebuilt program.