Integration & Perft validation

[Hardcode3]

🎯 Goal

Validate the entire pipeline.

🧠 Key Idea

Perft never lies.

🛠️ Tasks

• Integrate generate_legal_moves:

void generate_legal_moves(MoveList& moves, const Board& board, Color us) {
    Square king_sq = board.king_square(us);

    Bitboard checkers = attackers_to(king_sq, board, opposite(us));

    Bitboard check_mask = compute_check_mask(king_sq, checkers);

    Bitboard pinned;
    Bitboard pin_ray[64] = {0};
    compute_pins(king_sq, board, us, pinned, pin_ray);

    generate_legal_king_moves(moves, board, us, check_mask);

    if (popcount(checkers) > 1)
        return;

    generate_legal_knight_moves(moves, board, us, check_mask, pinned, pin_ray);
    generate_legal_bishop_moves(moves, board, us, check_mask, pinned, pin_ray);
    generate_legal_rook_moves(moves, board, us, check_mask, pinned, pin_ray);
    generate_legal_queen_moves(moves, board, us, check_mask, pinned, pin_ray);
    generate_legal_pawn_moves(moves, board, us, check_mask, pinned, pin_ray);

    generate_legal_castling_moves(moves, board, us, checkers);
}

• Run perft (depth 1 -> 5)
• Compare against known references

✅ Acceptance Criteria

• Exact perft numbers
• No illegal moves generated