fix(app): 18 处 catch(e) 添加 debugPrint 异常日志

- parent_bloc: 6 处 (LoadChildren/BindChild/ViewJournals/ExportData/DeleteData/UnbindChild)
- search_bloc: 3 处 (SearchByMood/SearchByTag/SearchByKeyword)
- achievement_bloc: 1 处 (_fetchAchievements)
- sticker_bloc: 2 处 (_fetchPacks/fetchStickersInPack)
- template_bloc: 1 处 (_fetchTemplates)
- mood_bloc: 1 处 (_loadStats)
- home_bloc: 1 处 (_onLoadData)
- calendar_bloc: 1 处 (_onMonthChanged)
- sync_engine: 1 处 (trySync)
- weekly_page: 已有 debugPrint，无需修改

app/lib/features/parent/bloc/parent_bloc.dart

@@ -3,6 +3,7 @@
 // 状态机: ParentInitial → ParentLoading → ParentChildrenLoaded / ParentJournalsLoaded / ParentDataExported / ParentDataDeleted / ParentError
 // API: /diary/parent/* 端点
 
+import 'package:flutter/foundation.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
 import '../../../data/remote/api_client.dart';
@@ -40,6 +41,7 @@ class ParentBloc extends Bloc<ParentEvent, ParentState> {
           .toList();
       emit(ParentChildrenLoaded(children));
     } catch (e) {
+      debugPrint('ParentBloc._onLoadChildren 失败: $e');
       emit(const ParentError('加载孩子列表失败'));
     }
   }
@@ -57,6 +59,7 @@ class ParentBloc extends Bloc<ParentEvent, ParentState> {
       // 绑定成功后重新加载列表
       add(const ParentLoadChildren());
     } catch (e) {
+      debugPrint('ParentBloc._onBindChild 失败: $e');
       emit(const ParentError('绑定失败，请检查孩子 ID'));
     }
   }
@@ -83,6 +86,7 @@ class ParentBloc extends Bloc<ParentEvent, ParentState> {
         journals: items.cast<Map<String, dynamic>>(),
       ));
     } catch (e) {
+      debugPrint('ParentBloc._onViewJournals 失败: $e');
       emit(const ParentError('加载日记失败'));
     }
   }
@@ -103,6 +107,7 @@ class ParentBloc extends Bloc<ParentEvent, ParentState> {
         data: response.data as Map<String, dynamic>,
       ));
     } catch (e) {
+      debugPrint('ParentBloc._onExportData 失败: $e');
       emit(const ParentError('导出失败'));
     }
   }
@@ -119,6 +124,7 @@ class ParentBloc extends Bloc<ParentEvent, ParentState> {
       });
       emit(ParentDataDeleted(event.childId));
     } catch (e) {
+      debugPrint('ParentBloc._onDeleteData 失败: $e');
       emit(const ParentError('删除失败'));
     }
   }
@@ -134,6 +140,7 @@ class ParentBloc extends Bloc<ParentEvent, ParentState> {
       });
       add(const ParentLoadChildren());
     } catch (e) {
+      debugPrint('ParentBloc._onUnbindChild 失败: $e');
       emit(const ParentError('解绑失败'));
     }
   }