config：更新核心配置支持网格系统

- EventNames添加网格相关事件定义
- ProjectPaths添加网格系统和地形资源路径

_Core/EventNames.gd

@@ -51,6 +51,8 @@ const SCENE_DATA_TRANSFER = "scene_data_transfer"
 const TILEMAP_READY = "tilemap_ready"
 const COMPONENT_MESSAGE = "component_message"
 const POSITION_UPDATE = "position_update"
+const GRID_POSITION_CHANGED = "grid_position_changed"
+const GRID_SNAP_REQUESTED = "grid_snap_requested"
 
 # ============================================================================
 # 测试事件