Engine: Card a farby/hodnoty su hashovatelne

Vlastne __eq__ rusilo zdedeny __hash__, takze karty ani enumy sa nedali
pouzit ako kluce dictov a v setoch. Hash doplneny konzistentne s __eq__.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_engine.py

@@ -121,6 +121,16 @@ class StashCase(unittest.TestCase):
         self.assertRaises(BridzikException, s.get_active_player)
 
 
+class CardCase(unittest.TestCase):
+    def test_hashable_consistent_with_eq(self):
+        # vlastne __eq__ nesmie zrusit hashovatelnost (dict/set pouzitie)
+        heart_7 = Card(Card_colors['HEARTS'], Card_values['C7'])
+        self.assertEqual(hash(heart_7), hash(Card(Card_colors['HEARTS'], Card_values['C7'])))
+        self.assertEqual(len(set(cards)), 32)
+        self.assertEqual({Card_colors['HEARTS']: 1}[Card_colors['HEARTS']], 1)
+        self.assertEqual({Card_values['ACE']: 1}[Card_values['ACE']], 1)
+
+
 class RoundCase(unittest.TestCase):
     def test_round_constructor(self):
         self.assertRaises(BridzikException, Round, round_number=8, first_player=0)