fix(14-1): remove '0' ball button from end-of-turn grid

- The '0' button is no longer shown in the 'Bälle am Ende der Aufnahme' grid
- Only buttons for 1–15 balls are now available, matching real game scenarios

Refs #26

src/components/GameDetail141.jsx

@@ -183,7 +183,7 @@ const GameDetail141 = ({ game, onUpdate, onUndo, onForfeit, onBack }) => {
       <div className={styles['potted-balls-container']}>
         <p className={styles['potted-balls-header']}>Bälle am Ende der Aufnahme:</p>
         <div className={styles['potted-balls-grid']}>
-          {Array.from({ length: 16 }, (_, i) => i).map(num => (
+          {Array.from({ length: 15 }, (_, i) => i + 1).map(num => (
             <button
               key={num}
               onClick={() => handleTurnEnd(num)}