Enforce Turn-Based Logic and Player Order

[aji70]

📚 Overview
Currently, methods like roll_dice or buy_property do not validate that it's the caller's turn. Enforcing strict turn-based rules is critical to ensure fairness and gameplay integrity in a multiplayer Monopoly setting.

🛠️ Tasks

Store and track current turn index per game.

Prevent actions from players out of turn.

Advance the turn after successful moves.

Support skipping turns or ending them explicitly.

✅ Definition of Done

Only the current player can take a turn.

Turns rotate correctly through the player list.

Game remains fair and predictable in multiplayer.