Replace Situation parameter with GameContext across all RuleSet methods
to align with the new game state abstraction. Updated imports to use the
api module's types (GameContext, Square, Move).
StandardRules will need to be updated in Task 3 to implement the new
interface signature and use api types instead of maichess.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Bundles complete game state (board, turn, castling rights, en passant, halfMoveClock, moves)
with immutable builder methods for functional state transitions.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>