- crypto: encrypt/decrypt roundtrip, empty data, size formula, HMAC compute/verify, SHA-256 known values - compression: compress/decompress roundtrip, empty data, large data, should_compress heuristic - format: header write/read roundtrip, TOC entry roundtrip (ASCII + Cyrillic + empty name), bad magic/version rejection, entry size calculation matching FORMAT.md worked example - Update hex-literal to v1.1