feat(pathfinding): 添加寻路系统模块 (#333)

* feat(pathfinding): 添加寻路系统模块

实现完整的寻路系统，支持 A* 算法、网格地图、导航网格和路径平滑:

A* 寻路算法:
- 高效的二叉堆优先队列
- 可配置的启发式权重
- 最大搜索节点限制
- 支持对角移动和穿角避免

网格地图 (GridMap):
- 基于二维数组的网格地图
- 支持 4 方向和 8 方向移动
- 可变移动代价
- 从数组或字符串加载地图

导航网格 (NavMesh):
- 凸多边形导航网格
- 自动检测相邻多边形
- 漏斗算法路径优化
- 适合复杂地形

路径平滑:
- Bresenham 视线检测
- 射线投射视线检测
- 视线简化器 (移除不必要的拐点)
- Catmull-Rom 曲线平滑
- 组合平滑器

启发式函数:
- 曼哈顿距离 (4方向)
- 欧几里得距离 (任意方向)
- 切比雪夫距离 (8方向)
- 八角距离 (8方向，对角线√2)

蓝图节点 (8个):
- FindPath: 基础寻路
- FindPathSmooth: 平滑寻路
- IsWalkable: 检查可通行性
- GetPathLength: 获取路径点数
- GetPathDistance: 获取路径距离
- GetPathPoint: 获取路径点
- MoveAlongPath: 沿路径移动
- HasLineOfSight: 视线检测

* chore: update pnpm-lock.yaml for pathfinding package

packages/pathfinding/module.json

@@ -0,0 +1,24 @@
+{
+    "id": "pathfinding",
+    "name": "@esengine/pathfinding",
+    "globalKey": "pathfinding",
+    "displayName": "Pathfinding",
+    "description": "寻路系统，提供 A*、网格地图、导航网格和路径平滑 | Pathfinding system with A*, grid map, NavMesh and path smoothing",
+    "version": "1.0.0",
+    "category": "AI",
+    "icon": "Route",
+    "tags": ["pathfinding", "navigation", "astar", "navmesh", "ai"],
+    "isCore": false,
+    "defaultEnabled": true,
+    "isEngineModule": true,
+    "canContainContent": false,
+    "platforms": ["web", "desktop", "mobile"],
+    "dependencies": ["core", "math", "blueprint"],
+    "exports": {
+        "components": ["PathfindingAgentComponent"],
+        "systems": ["PathfindingSystem"]
+    },
+    "requiresWasm": false,
+    "outputPath": "dist/index.js",
+    "pluginExport": "PathfindingPlugin"
+}