feat(game-14.1): Implement undo, forfeit, log, and stats

- Implements a robust undo feature using a state stack.
- Adds a 'Forfeit' button to allow a player to concede the game.
- Introduces a 'Game Log' to track all turns, fouls, and re-racks.
- Calculates and displays post-game statistics (highest run, avg. pots/turn).
- All changes are related to issue #21.

src/components/GameCompletionModal.module.css

@@ -34,9 +34,10 @@
     font-weight: 700;
 }
 .winner-announcement h3 {
-    font-size: 1.2rem;
     margin: 0;
-    color: #fff;
+    font-size: 1.5rem;
+    color: #2c3e50;
+    text-align: center;
 }
 .btn {
     flex: 1;
@@ -64,4 +65,46 @@
         font-size: 1rem;
         padding: 14px 0;
     }
+}
+
+.stats-container {
+    margin-top: 1.5rem;
+    padding-top: 1rem;
+    border-top: 1px solid #dee2e6;
+}
+
+.stats-title {
+    text-align: center;
+    font-size: 1.3rem;
+    color: #495057;
+    margin-bottom: 1rem;
+}
+
+.player-stats {
+    margin-bottom: 1rem;
+    padding: 0.75rem;
+    background-color: #f8f9fa;
+    border-radius: 4px;
+}
+
+.player-name-stats {
+    font-weight: bold;
+    margin-bottom: 0.5rem;
+    color: #343a40;
+}
+
+.stat-item {
+    display: flex;
+    justify-content: space-between;
+    font-size: 0.95rem;
+    color: #6c757d;
+}
+
+.stat-item strong {
+    color: #212529;
+}
+
+.btn {
+    padding: 0.75rem 1.5rem;
+    border-radius: 4px;
 }