Snakes and Ladders: Check board positions should not be active while on options screen

[jage9]

The check positions command C should not be active or available until the game has started. It currently is available on the options screen. An easy fix mirroring other games.

[olsonale]

This appears to have been fixed in commit a542607 ("Refine Farkle bot policy and gate Snakes position checks"), which:

1. Changed the "C" keybind from KeybindState.ALWAYS to KeybindState.ACTIVE so it only works during gameplay
2. Added _is_check_positions_enabled to return "action-not-playing" when the game hasn't started
3. Added tests verifying both behaviors

This issue may be stale and ready to close.