feat(blueprint, node-editor): 重构蓝图装饰器系统，添加 Shadow DOM 支持 (#430)

**blueprint**
- 移除 Reflect.getMetadata 依赖，装饰器要求显式指定类型
- 新增 ECS 节点：Entity、Component、Flow 控制节点
- 新增组件自动注册系统 (BlueprintExpose, BlueprintProperty, BlueprintMethod)
- 删除未实现的事件节点占位文件

**node-editor**
- 新增 injectNodeEditorStyles() 函数支持 Shadow DOM 样式注入
- 导出 nodeEditorCssText 用于手动样式注入

packages/devtools/node-editor/src/components/editor/NodeEditor.tsx

@@ -1,4 +1,4 @@
-import React, { useRef, useCallback, useState, useMemo } from 'react';
+import React, { useRef, useCallback, useState, useMemo, useEffect } from 'react';
 import { Graph } from '../../domain/models/Graph';
 import { GraphNode, NodeTemplate } from '../../domain/models/GraphNode';
 import { Connection } from '../../domain/models/Connection';
@@ -127,6 +127,18 @@ export const NodeEditor: React.FC<NodeEditorProps> = ({
     const [connectionDrag, setConnectionDrag] = useState<ConnectionDragState | null>(null);
     const [hoveredPin, setHoveredPin] = useState<Pin | null>(null);
 
+    // Force re-render after mount to ensure connections are drawn correctly
+    // 挂载后强制重渲染以确保连接线正确绘制
+    const [, forceUpdate] = useState(0);
+    useEffect(() => {
+        // Use requestAnimationFrame to wait for DOM to be fully rendered
+        // 使用 requestAnimationFrame 等待 DOM 完全渲染
+        const rafId = requestAnimationFrame(() => {
+            forceUpdate(n => n + 1);
+        });
+        return () => cancelAnimationFrame(rafId);
+    }, [graph.id]);
+
     /**
      * Converts screen coordinates to canvas coordinates
      * 将屏幕坐标转换为画布坐标

packages/devtools/node-editor/src/index.ts

@@ -10,6 +10,9 @@
 // Import styles (导入样式)
 import './styles/index.css';
 
+// CSS utilities for Shadow DOM (Shadow DOM 的 CSS 工具)
+export { nodeEditorCssText, injectNodeEditorStyles } from './styles/cssText';
+
 // Domain models (领域模型)
 export {
     // Models

packages/devtools/node-editor/src/styles/cssText.ts

@@ -0,0 +1,55 @@
+/**
+ * @zh 节点编辑器 CSS 样式文本
+ * @en Node Editor CSS style text
+ *
+ * @zh 此文件在构建时由 vite 插件自动生成
+ * @en This file is auto-generated by vite plugin during build
+ */
+
+// Placeholder - will be replaced by vite plugin during build
+export const nodeEditorCssText = '__NODE_EDITOR_CSS_PLACEHOLDER__';
+
+/**
+ * @zh 将 CSS 注入到指定的根节点（支持 Shadow DOM）
+ * @en Inject CSS into specified root node (supports Shadow DOM)
+ *
+ * @param root - @zh 目标根节点（Document 或 ShadowRoot）@en Target root node (Document or ShadowRoot)
+ * @param styleId - @zh 样式标签的 ID @en ID for the style tag
+ * @returns @zh 创建的 style 元素 @en The created style element
+ *
+ * @example
+ * ```typescript
+ * // Inject into Shadow DOM
+ * const shadowRoot = element.attachShadow({ mode: 'open' });
+ * injectNodeEditorStyles(shadowRoot);
+ *
+ * // Inject into document (with custom ID)
+ * injectNodeEditorStyles(document, 'my-editor-styles');
+ * ```
+ */
+export function injectNodeEditorStyles(
+    root: Document | ShadowRoot | DocumentFragment,
+    styleId: string = 'esengine-node-editor-styles'
+): HTMLStyleElement | null {
+    // Check if already injected
+    const existingStyle = (root as any).getElementById?.(styleId) ||
+        (root as any).querySelector?.(`#${styleId}`);
+    if (existingStyle) {
+        return existingStyle as HTMLStyleElement;
+    }
+
+    // Create and inject style element
+    const style = document.createElement('style');
+    style.id = styleId;
+    style.textContent = nodeEditorCssText;
+
+    if ('head' in root) {
+        // Document
+        (root as Document).head.appendChild(style);
+    } else {
+        // ShadowRoot or DocumentFragment
+        root.appendChild(style);
+    }
+
+    return style;
+}