feat(app): WASDMove script (WASD camera-relative movement)

ScriptBehavior gains App() host access (Application injected via
ScriptRuntime), TryGet<T> and EntityBits for physics facade addressing.
WASDMove maps WASD to the editor camera's horizontal heading (UE
gameplay convention): dynamic bodies go through the physics velocity
facade preserving the vertical component (zeroing Y would cancel
gravity mid-fall), bodiless entities translate their transform directly.
Editor-mode key conflict is naturally avoided: RMB-held flight consumes
WASD, release hands keys to the script.

Engine/include/Engine/Scripting/Script.h

@@ -27,6 +27,9 @@
 #include <vector>
 
 namespace Engine {
+
+    class Application;   // 宿主门面（Window/Renderer/Physics 入口），实现见 ScriptRuntime.cpp
+
     namespace Scripting {
 
         class ScriptBehavior {
@@ -52,17 +55,32 @@ namespace Engine {
                 return m_Scene->GetRegistry().get<T>(m_Entity);
             }
 
+            template<typename T>
+            T* TryGet() {
+                return m_Scene->GetRegistry().try_get<T>(m_Entity);
+            }
+
+            // 绑定实体的 entityBits（物理门面按键值寻址）
+            u32 EntityBits() const {
+                return static_cast<u32>(entt::to_integral(m_Entity));
+            }
+
+            // 宿主应用（GetWindow/GetRenderer/GetPhysics/GetScene……）
+            Application& App() const;
+
             bool Valid() const { return m_Scene != nullptr && m_Entity != entt::null; }
 
         private:
             friend class ScriptRuntime;
-            void Bind(ECS::Scene& scene, entt::entity e) {
+            void Bind(ECS::Scene& scene, entt::entity e, Application* app) {
                 m_Scene = &scene;
                 m_Entity = e;
+                m_App = app;
             }
 
             ECS::Scene* m_Scene = nullptr;
             entt::entity m_Entity = entt::null;
+            Application* m_App = nullptr;
         };
 
         // ---- 按名注册表：脚本类文件级自注册，运行时按名实例化 ----

Engine/include/Engine/Scripting/ScriptRuntime.h

@@ -14,6 +14,9 @@
 #include <unordered_map>
 
 namespace Engine {
+
+    class Application;
+
     namespace Scripting {
 
         // 实例簿记：行为对象 + OnCreate 是否已调
@@ -24,7 +27,8 @@ namespace Engine {
 
         class ScriptRuntime {
         public:
-            explicit ScriptRuntime(ECS::Scene& scene) : m_Scene(scene) {}
+            explicit ScriptRuntime(ECS::Scene& scene, Application* app = nullptr)
+                : m_Scene(scene), m_App(app) {}
 
             // 每帧调用（吃 scaled dt）：对账 → OnCreate（新实例）→ OnUpdate
             void Update(f32 dt);
@@ -33,6 +37,7 @@ namespace Engine {
             void Sync();
 
             ECS::Scene& m_Scene;
+            Application* m_App;                                   // 注入脚本上下文
             std::unordered_map<u32, ScriptInstance> m_Instances; // entityBits
         };