Refactor/clean architecture phase1 (#215)

* refactor(editor): 建立Clean Architecture领域模型层

* refactor(editor): 实现应用层架构 - 命令模式、用例和状态管理

* refactor(editor): 实现展示层核心Hooks

* refactor(editor): 实现基础设施层和展示层组件

* refactor(editor): 迁移画布和连接渲染到 Clean Architecture 组件

* feat(editor): 集成应用层架构和命令模式，实现撤销/重做功能

* refactor(editor): UI组件拆分

* refactor(editor): 提取快速创建菜单逻辑

* refactor(editor): 重构BehaviorTreeEditor，提取组件和Hook

* refactor(editor): 提取端口连接和键盘事件Hook

* refactor(editor): 提取拖放处理Hook

* refactor(editor): 提取画布交互Hook和工具函数

* refactor(editor): 完成核心重构

* fix(editor): 修复节点无法创建和连接

* refactor(behavior-tree,editor): 重构节点子节点约束系统，实现元数据驱动的架构

packages/editor-app/src/domain/value-objects/Position.ts

@@ -0,0 +1,72 @@
+/**
+ * 位置值对象
+ * 表示二维空间中的坐标点
+ */
+export class Position {
+    private readonly _x: number;
+    private readonly _y: number;
+
+    constructor(x: number, y: number) {
+        this._x = x;
+        this._y = y;
+    }
+
+    get x(): number {
+        return this._x;
+    }
+
+    get y(): number {
+        return this._y;
+    }
+
+    /**
+     * 创建新的位置，加上偏移量
+     */
+    add(offset: Position): Position {
+        return new Position(this._x + offset._x, this._y + offset._y);
+    }
+
+    /**
+     * 创建新的位置，减去偏移量
+     */
+    subtract(other: Position): Position {
+        return new Position(this._x - other._x, this._y - other._y);
+    }
+
+    /**
+     * 计算到另一个位置的距离
+     */
+    distanceTo(other: Position): number {
+        const dx = this._x - other._x;
+        const dy = this._y - other._y;
+        return Math.sqrt(dx * dx + dy * dy);
+    }
+
+    /**
+     * 值对象相等性比较
+     */
+    equals(other: Position): boolean {
+        return this._x === other._x && this._y === other._y;
+    }
+
+    /**
+     * 转换为普通对象
+     */
+    toObject(): { x: number; y: number } {
+        return { x: this._x, y: this._y };
+    }
+
+    /**
+     * 从普通对象创建
+     */
+    static fromObject(obj: { x: number; y: number }): Position {
+        return new Position(obj.x, obj.y);
+    }
+
+    /**
+     * 创建零位置
+     */
+    static zero(): Position {
+        return new Position(0, 0);
+    }
+}