feat(app): EditorPage 顶栏添加评语入口 — 仅已有日记显示

- 添加评语图标按钮（仅 journalId != null 时显示）
- 实现 _showComments 方法打开 CommentListSheet
- 补充 api_client + comment_list_sheet imports

app/lib/features/editor/views/editor_page.dart

@@ -19,9 +19,11 @@ import '../../../data/models/journal_element.dart';
 import '../../../data/models/journal_entry.dart' show JournalEntry, Mood;
 import '../../../data/repositories/journal_repository.dart';
 import '../../../data/repositories/class_repository.dart';
+import '../../../data/remote/api_client.dart';
 import '../../../data/services/sync_engine.dart';
 import '../../auth/bloc/auth_bloc.dart';
 import '../bloc/editor_bloc.dart';
+import '../widgets/comment_list_sheet.dart';
 import '../widgets/handwriting_canvas.dart';
 import '../widgets/stroke_model.dart';
 import '../widgets/draggable_element.dart';
@@ -427,6 +429,13 @@ class _EditorViewState extends State<_EditorView> {
                     onPressed: () => _showTagPanel(context, state),
                     constraints: const BoxConstraints(minWidth: 36, minHeight: 36),
                   ),
+                  // 评语按钮（仅已有日记显示）
+                  if (widget.journalId != null)
+                    IconButton(
+                      icon: const Icon(Icons.chat_bubble_outline_rounded, size: 18),
+                      onPressed: () => _showComments(context),
+                      constraints: const BoxConstraints(minWidth: 36, minHeight: 36),
+                    ),
                   // 完成/保存按钮
                   Padding(
                     padding: const EdgeInsets.only(left: 4),
@@ -464,6 +473,22 @@ class _EditorViewState extends State<_EditorView> {
     widget.onSaveComplete();
   }
 
+  /// 显示评论列表
+  void _showComments(BuildContext context) {
+    final journalId = widget.journalId;
+    if (journalId == null) return;
+
+    showModalBottomSheet(
+      context: context,
+      isScrollControlled: true,
+      backgroundColor: Colors.transparent,
+      builder: (_) => CommentListSheet(
+        journalId: journalId,
+        apiClient: context.read<ApiClient>(),
+      ),
+    );
+  }
+
   /// 格式化日期显示
   String _formatDate(EditorState state) {
     final now = DateTime.now();