PieceBlock

Identifies a single block within a piece. This is a pure-Kotlin port of libtorrent's piece_block (include/libtorrent/piece_block.hpp).

A piece is the unit the .torrent metadata hashes; a block is the unit a peer actually requests over the wire (16 KiB by default). pieceIndex is a plain piece index and blockIndex is the 0-based block offset inside that piece. Both are plain Int (v0 KiteTorrent does not use strong index types).

The C++ type defines a total order (piece first, then block) and value equality; we mirror both so blocks can live in sorted/hashed containers.