bug(Santorini): Display Debug

[cstorm125]

Properly displays board and valid moves for Santorini environment.
Previously, it was displaying incorrect initial board state for each player causing confusion for agent starting second.

[borgr]

Reworked to a minimal fix — ready to merge. I pushed a commit that keeps the real bug fix but drops the collateral changes.

The actual bug: the initial prompt showed game_state['valid_moves'], which reset() sets to _get_valid_moves(0). So every player was shown player 0's valid moves instead of their own. Fix:

if self.show_valid:
    prompt += f"\nValid moves: {self._get_valid_moves(player_id)}"

Why the rest was reverted: the previous version deleted the is_open/show_valid constructor options and only showed the board/moves to player 0 — which left every non-starting player with no board and no moves in their initial prompt (a new regression), and also threaded a valid_moves arg into create_board_str. Reverting those keeps the env's existing knobs and renderer signature intact; the net change is now a single line.

Verified on 3.11 (3-player): each player's prompt now matches _get_valid_moves(player_id) for their own workers (Navy / White / Grey are distinct); is_open=False, show_valid=False still suppresses both sections; make/reset/step cycle works. MERGEABLE / CLEAN.

[borgr]

Thanks for catching this, @cstorm125. I've rebased the one-line fix onto current main and opened #200 so it can merge cleanly — credit to you for the diagnosis. Happy to close this in favor of that, or land it here if you'd rather.