✅ Select contract demon none when no cards

Category	Ability
Status	Passing
Test	tests/test_turn_sequence.py::test_select_contract_demon_none_when_no_cards

Player with no cards contracts None (deck_exhaustion rule).

Preconditions

• P1 hand = [].

Action

• select_contract_demon(state, Side.PLAYER_1, None)

result = select_contract_demon(state, Side.PLAYER_1, None)

Expected Postconditions

• contracted_demons[P1] = None.

• P1 hand = [] (unchanged).

Assertions

assert result.contracted_demons[Side.PLAYER_1] is None
assert result.players[Side.PLAYER_1].hand == []