fix(app): Phase 1.1 紧急修复 — SyncEngine 接入 + authorId + catch 异常处理

- feat(sync): SyncEngine 接入 EditorPage, 保存时 enqueue + 网络恢复自动 trySync
- fix(editor): authorId 从 AuthBloc 获取, 替代硬编码 'local'
- fix(bloc): class_bloc/calendar/profile/parent catch(_).全部改为 debugPrint
- feat(editor): 编辑器工具栏拆分 (brush_panel/tag_panel/text_format_bar/dot_grid_painter)
- feat(editor): EditorBloc 扩展 + EditorPage 增强
- feat(search): SearchBloc 扩展搜索功能
- feat(home): HomeBloc/HomePage 增强
- feat(auth): LoginPage 增强
- feat(templates): TemplateGalleryPage 重构
- fix(web): 管理端班级/日记页面修复
- fix(server): comment_service + theme_handler 修复
- docs: 添加全链路审计报告和验证截图

app/lib/data/models/journal_entry.dart

@@ -42,6 +42,10 @@ class JournalEntry {
   final bool isPrivate;
   final bool sharedToClass;
   final String? assignedTopicId;
+
+  /// 内容摘要 — 自动从文本元素提取，用于列表预览
+  final String? contentExcerpt;
+
   final int version;
   final DateTime createdAt;
   final DateTime updatedAt;
@@ -58,6 +62,7 @@ class JournalEntry {
     this.isPrivate = true,
     this.sharedToClass = false,
     this.assignedTopicId,
+    this.contentExcerpt,
     this.version = 1,
     required this.createdAt,
     required this.updatedAt,
@@ -77,6 +82,8 @@ class JournalEntry {
     bool? sharedToClass,
     String? assignedTopicId,
     bool clearAssignedTopicId = false,
+    String? contentExcerpt,
+    bool clearContentExcerpt = false,
     int? version,
     DateTime? createdAt,
     DateTime? updatedAt,
@@ -94,6 +101,9 @@ class JournalEntry {
         sharedToClass: sharedToClass ?? this.sharedToClass,
         assignedTopicId:
             clearAssignedTopicId ? null : (assignedTopicId ?? this.assignedTopicId),
+        contentExcerpt: clearContentExcerpt
+            ? null
+            : (contentExcerpt ?? this.contentExcerpt),
         version: version ?? this.version,
         createdAt: createdAt ?? this.createdAt,
         updatedAt: updatedAt ?? this.updatedAt,
@@ -111,6 +121,7 @@ class JournalEntry {
         'is_private': isPrivate,
         'shared_to_class': sharedToClass,
         'assigned_topic_id': assignedTopicId,
+        'content_excerpt': contentExcerpt,
         'version': version,
         'created_at': createdAt.toIso8601String(),
         'updated_at': updatedAt.toIso8601String(),
@@ -134,6 +145,7 @@ class JournalEntry {
         isPrivate: (json['is_private'] as bool?) ?? true,
         sharedToClass: (json['shared_to_class'] as bool?) ?? false,
         assignedTopicId: json['assigned_topic_id'] as String?,
+        contentExcerpt: json['content_excerpt'] as String?,
         version: (json['version'] as int?) ?? 1,
         createdAt: DateTime.parse(json['created_at'] as String),
         updatedAt: DateTime.parse(json['updated_at'] as String),