feat: 添加导出图层功能，支持将图层转换为位图图像并下载

src/component/Canvas/CanvasEditor/components/ToolsSidebar.vue

@@ -2,6 +2,19 @@
 import { ref, inject, computed, onMounted, onUnmounted } from "vue";
 import { OperationType } from "../utils/layerHelper";
 
+const emit = defineEmits([
+  "tool-selected",
+  "trigger-image-upload",
+  "add-text",
+  "undo",
+  "redo",
+  "toggle-minimap",
+  "zoom-in",
+  "zoom-out",
+  "toggle-red-green-mode",
+  "undo-redo-status-changed",
+]);
+
 const props = defineProps({
   activeTool: String,
   minimapEnabled: {
@@ -24,24 +37,18 @@ const canRedo = ref(false);
 commandManager.setChangeCallback((info) => {
   canUndo.value = info.canUndo;
   canRedo.value = info.canRedo;
+
+  emit("undo-redo-status-changed", {
+    canUndo: canUndo.value,
+    canRedo: canRedo.value,
+    commandManager,
+  });
 });
 
 // 撤销/重做操作
 const undoFun = () => commandManager.undo();
 const redoFun = () => commandManager.redo();
 
-const emit = defineEmits([
-  "tool-selected",
-  "trigger-image-upload",
-  "add-text",
-  "undo",
-  "redo",
-  "toggle-minimap",
-  "zoom-in",
-  "zoom-out",
-  "toggle-red-green-mode",
-]);
-
 // 普通模式工具列表
 const normalToolsList = ref([
   {