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

_Core/ProjectPaths.gd

@@ -19,6 +19,11 @@ const CORE_SYSTEMS = CORE_ROOT + "systems/"
 const CORE_COMPONENTS = CORE_ROOT + "components/"
 const CORE_UTILS = CORE_ROOT + "utils/"
 
+# 系统文件路径
+const GRID_SYSTEM = CORE_SYSTEMS + "GridSystem.gd"
+const EVENT_SYSTEM = CORE_SYSTEMS + "EventSystem.gd"
+const TILE_SYSTEM = CORE_SYSTEMS + "TileSystem.gd"
+
 # ============================================================================
 # 场景路径
 # ============================================================================
@@ -46,6 +51,10 @@ const ASSETS_FONTS = ASSETS_ROOT + "fonts/"
 const ASSETS_MATERIALS = ASSETS_ROOT + "materials/"
 const ASSETS_SHADERS = ASSETS_ROOT + "shaders/"
 
+# 地形资源路径
+const ASSETS_TERRAIN = ASSETS_SPRITES + "terrain/"
+const ASSETS_GRASS = ASSETS_TERRAIN + "grass/"
+
 # ============================================================================
 # 数据路径
 # ============================================================================