refactor(ui): mobile_carousel_layout.dart 분할 (1220→689 LOC)

- RetroSelectDialog, RetroOptionItem: 선택 다이얼로그
- RetroSoundDialog: 사운드 설정 다이얼로그
- RetroConfirmDialog: 확인 다이얼로그
- RetroMenuSection, RetroMenuItem, RetroSpeedChip: 메뉴 위젯

lib/src/features/game/widgets/dialogs/retro_confirm_dialog.dart

@@ -0,0 +1,97 @@
+import 'package:flutter/material.dart';
+
+import 'package:asciineverdie/src/shared/retro_colors.dart';
+import 'package:asciineverdie/src/shared/widgets/retro_widgets.dart';
+
+/// 레트로 스타일 확인 다이얼로그
+class RetroConfirmDialog extends StatelessWidget {
+  const RetroConfirmDialog({
+    super.key,
+    required this.title,
+    required this.message,
+    required this.confirmText,
+    required this.cancelText,
+    required this.onConfirm,
+    required this.onCancel,
+  });
+
+  final String title;
+  final String message;
+  final String confirmText;
+  final String cancelText;
+  final VoidCallback onConfirm;
+  final VoidCallback onCancel;
+
+  @override
+  Widget build(BuildContext context) {
+    final background = RetroColors.backgroundOf(context);
+    final gold = RetroColors.goldOf(context);
+
+    return Dialog(
+      backgroundColor: Colors.transparent,
+      child: Container(
+        constraints: const BoxConstraints(maxWidth: 360),
+        decoration: BoxDecoration(
+          color: background,
+          border: Border.all(color: gold, width: 3),
+        ),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            // 타이틀
+            Container(
+              width: double.infinity,
+              padding: const EdgeInsets.all(12),
+              color: gold.withValues(alpha: 0.2),
+              child: Text(
+                title,
+                style: TextStyle(
+                  fontFamily: 'PressStart2P',
+                  fontSize: 10,
+                  color: gold,
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ),
+            // 메시지
+            Padding(
+              padding: const EdgeInsets.all(16),
+              child: Text(
+                message,
+                style: TextStyle(
+                  fontFamily: 'PressStart2P',
+                  fontSize: 16,
+                  color: RetroColors.textPrimaryOf(context),
+                  height: 1.8,
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ),
+            // 버튼
+            Padding(
+              padding: const EdgeInsets.fromLTRB(12, 0, 12, 12),
+              child: Row(
+                children: [
+                  Expanded(
+                    child: RetroTextButton(
+                      text: cancelText,
+                      isPrimary: false,
+                      onPressed: onCancel,
+                    ),
+                  ),
+                  const SizedBox(width: 8),
+                  Expanded(
+                    child: RetroTextButton(
+                      text: confirmText,
+                      onPressed: onConfirm,
+                    ),
+                  ),
+                ],
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}