주석화 진행상황 정리하고 핵심 모듈에 한글 주석 추가

lib/widgets/app_shell.dart

@@ -6,6 +6,7 @@ import '../core/constants/app_sections.dart';
 import '../core/theme/theme_controller.dart';
 import '../core/permissions/permission_manager.dart';
 
+/// 앱 기본 레이아웃을 제공하는 셸 위젯. 사이드 네비게이션과 AppBar를 구성한다.
 class AppShell extends StatelessWidget {
   const AppShell({
     super.key,
@@ -248,10 +249,17 @@ class _ThemeMenuButton extends StatelessWidget {
             (value) => PopupMenuItem<ThemeMode>(
               value: value,
               child: Row(
+                mainAxisSize: MainAxisSize.min,
                 children: [
                   Icon(_icon(value), size: 18),
                   const SizedBox(width: 8),
-                  Text(_label(value)),
+                  Flexible(
+                    child: Text(
+                      _label(value),
+                      maxLines: 1,
+                      overflow: TextOverflow.ellipsis,
+                    ),
+                  ),
                 ],
               ),
             ),
@@ -265,10 +273,18 @@ class _ThemeMenuButton extends StatelessWidget {
         ),
         child: Row(
           mainAxisAlignment: MainAxisAlignment.center,
+          mainAxisSize: MainAxisSize.min,
           children: [
             Icon(icon, size: 18),
             const SizedBox(width: 8),
-            Text('테마 · $label', style: theme.textTheme.labelSmall),
+            Flexible(
+              child: Text(
+                '테마 · $label',
+                style: theme.textTheme.labelSmall,
+                maxLines: 1,
+                overflow: TextOverflow.ellipsis,
+              ),
+            ),
           ],
         ),
       ),