Fix segmentation fault in TicTacToe minimax due to incorrect board state handling

[satyajit1288]

Problem

The TicTacToe implementation was causing a segmentation fault during the computer's turn.

Root Cause

The minimax() function was operating on the shared Game::board instead of using simulated board states during recursive evaluation. This caused incorrect recursion behavior and eventual stack overflow.

Solution

• Updated minimax() to accept Board state as a parameter.
• Ensured recursive calls operate on copied board instances.
• Removed dependency on shared mutable Game::board during simulation.

Impact

• Prevents segmentation fault during computer's turn
• Ensures correct state isolation in recursive minimax() evaluation
• Improves correctness and robustness of move simulation