v0.1.3

Direct PGN extraction on Database façade, high-performance binary-search multi-player filtering (Filter::PlayerSet), and 0-ply score-only game contract.

Added

• Database::game_pgn & Database::game_pgn_with, generating complete, valid PGN strings (Seven-Tag Roster, optional event/site/eco/round metadata, and formatted move text) directly from raw .cbh and .cbg bytes without requiring consumer-side move re-encoding.
• Filter::PlayerSet(IdSet), providing zero-allocation $O(\log K)$ binary-search matching over sorted candidate player IDs for multi-name queries.
• Score-only (0-ply) game contract, ensuring games without move bytes (e.g. historical games like Staunton–Hughes 1858) emit valid PGN headers with [PlyCount "0"] matching official ChessBase export behavior instead of silently skipping them.

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Full Changelog: v0.1.2...v0.1.3