XP-Modell nach VOD-Daten: 1->2 kostet 2 XP, Carousels geben keine XP

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

backend/tests/test_game.py

@@ -195,14 +195,16 @@ def test_pve_freezes_streak_and_pays_no_win_bonus(art, cfg):
 
 
 def test_natural_level_progression(art, cfg):
-    """Ohne XP-Kauf: Level 1 bei 1-2, Level 4 bei 2-1, Level 5 mit 6/20 bei 3-2."""
+    """Ohne XP-Kauf, laut VOD: 1-3 Lvl 2, 1-4 Lvl 3, 2-1 Lvl 3 (2/6), 2-5 Lvl 4 (2/10)."""
     game = Game(art, cfg, seed=6)
-    assert game.player.level == 1 and game.player.xp == 2  # 1-1-XP gebankt
+    assert game.player.level == 1 and game.player.xp == 0  # 1-1 gibt keine XP
     checks = {}
     while not game.over and game.round["label"] != "3-3":
         checks[game.round["label"]] = (game.player.level, game.player.xp)
         game.step()
-    assert checks["1-2"][0] == 1
-    assert checks["1-3"][0] == 3  # gratis Level 2 + kaskadierte XP
-    assert checks["2-1"] == (4, 0)
-    assert checks["3-2"] == (5, 6)
+    assert checks["1-2"] == (1, 0)
+    assert checks["1-3"] == (2, 0)
+    assert checks["1-4"] == (3, 0)
+    assert checks["2-1"] == (3, 2)
+    assert checks["2-5"] == (4, 2)
+    assert checks["3-2"] == (5, 0)