fix(app): 修复 4 个 Flutter 交互问题

1. 首页数据不刷新 — JournalRepository 添加 onJournalChanged
   Stream 变更通知，HomeBloc 订阅后自动刷新
2. 画笔再次点击不弹出面板 — 添加 ToolReactivated 事件，
   工具栏检测已激活工具时发出重新激活信号
3. 钢笔铅笔效果一样 — 调整 perfect_freehand 参数
   (pen: size 10/smooth 0.65, pencil: size 3/smooth 0.35)
4. 橡皮擦不生效 — ActiveStrokePainter 橡皮擦模式绘制
   半透明灰色反馈，笔画完成后 setState 触发 Layer 1 重绘
5. 贴纸文字无法缩放 — DraggableElement 用 Scale 手势
   替换 Pan 手势，支持双指缩放和旋转

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

@@ -625,6 +625,7 @@ class _EditorStack extends StatefulWidget {
 
 class _EditorStackState extends State<_EditorStack> {
   EditorTool? _lastTool;
+  int _lastReactivatedAt = 0;
   late final TextEditingController _titleController;
 
   @override
@@ -675,6 +676,26 @@ class _EditorStackState extends State<_EditorStack> {
       });
     }
     _lastTool = currentTool;
+
+    // 工具重新激活（再次点击已选中的工具）→ 重新弹出面板
+    final reactivatedAt = widget.state.toolReactivatedAt;
+    if (reactivatedAt != _lastReactivatedAt) {
+      _lastReactivatedAt = reactivatedAt;
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (!mounted) return;
+
+        switch (currentTool) {
+          case EditorTool.brush:
+            _showBrushPanel();
+          case EditorTool.sticker:
+            _showStickerPicker();
+          case EditorTool.more:
+            _showMoreSheet();
+          default:
+            break;
+        }
+      });
+    }
   }
 
   /// 显示贴纸选择底部面板
@@ -962,6 +983,19 @@ class _EditorStackState extends State<_EditorStack> {
               positionY: y,
             ));
           },
+          onResized: (id, w, h) {
+            context.read<EditorBloc>().add(ElementResized(
+              elementId: id,
+              width: w,
+              height: h,
+            ));
+          },
+          onRotated: (id, r) {
+            context.read<EditorBloc>().add(ElementRotated(
+              elementId: id,
+              rotation: r,
+            ));
+          },
           onDeleted: (id) {
             context.read<EditorBloc>().add(ElementRemoved(id));
           },