feat(engine): C++ native script system (ScriptBehavior + registry)

ScriptComponent stores only a script name string (POD, serializable);
instances are reconciled by ScriptRuntime each frame (PhysicsWorld
pattern): orphan/rename cleanup with OnDestroy, per-name instantiation
from a file-level self-registering registry (ENGINE_REGISTER_SCRIPT),
OnCreate on bind, OnUpdate after physics step on scaled dt. Engine
framerate loop only sees the base interface, so future Lua/C# behaviors
plug in as foreign ScriptBehavior implementations with zero engine
changes. Ships a Spinner sample script and Inspector script picker.

Engine/src/Core/Application.cpp

@@ -7,6 +7,7 @@
 #include <Engine/Core/Log.h>
 #include <Engine/ECS/Scene.h>
 #include <Engine/Physics/PhysicsWorld.h>
+#include <Engine/Scripting/ScriptRuntime.h>
 #include <Engine/Renderer/Renderer.h>
 #include <Engine/Assets/AssetManager.h>
 #include <Engine/Vulkan/Device.h>
@@ -102,6 +103,9 @@ namespace Engine {
         // 物理调试图元 → 渲染侧（PhysicsDebugPass 每帧上传绘制）
         m_Renderer->SetPhysicsDebugSource(&m_Physics->GetDebugFrame());
 
+        // 脚本生命周期（对账式，组件增删/改名即时生效）
+        m_Scripts = CreateScope<Scripting::ScriptRuntime>(*m_Scene);
+
         while (m_Running) {
             const auto frameStart = std::chrono::steady_clock::now();
 
@@ -121,6 +125,10 @@ namespace Engine {
             // SyncScene 对账仍跑（拖静态体照常同步）
             m_Physics->Step(frame.Dt());
 
+            // 脚本更新（物理之后、业务 OnUpdate 之前，Unity FixedUpdate→Update
+            // 语义；吃 scaled dt——timeScale=0 暂停时 dt=0 脚本自然停摆）
+            m_Scripts->Update(frame.Dt());
+
             OnUpdate(frame);
 
             // 延迟销毁在渲染前统一 flush，保证渲染遍历时池结构不变

Engine/src/Scripting/ScriptRuntime.cpp

@@ -0,0 +1,75 @@
+//
+// ScriptRuntime.cpp：脚本对账与生命周期驱动。
+//
+
+#include <Engine/Scripting/ScriptRuntime.h>
+
+#include <Engine/Core/Log.h>
+#include <Engine/ECS/Components.h>
+
+namespace Engine {
+    namespace Scripting {
+
+        void ScriptRuntime::Update(f32 dt) {
+            Sync();
+
+            auto& reg = m_Scene.GetRegistry();
+            for (auto& [bits, inst] : m_Instances) {
+                const auto e = static_cast<entt::entity>(bits);
+                if (!reg.valid(e) || !reg.any_of<ECS::ScriptComponent>(e)) {
+                    continue; // 延迟销毁队列里，下帧 Sync 清理
+                }
+                if (!inst.created) {
+                    inst.behavior->OnCreate();
+                    inst.created = true;
+                }
+                inst.behavior->OnUpdate(dt);
+            }
+        }
+
+        void ScriptRuntime::Sync() {
+            auto& reg = m_Scene.GetRegistry();
+
+            // 1. 孤儿/改名清理：实体或组件没了、脚本名变了 → OnDestroy + 删除
+            for (auto it = m_Instances.begin(); it != m_Instances.end();) {
+                const auto e = static_cast<entt::entity>(it->first);
+                const ECS::ScriptComponent* sc =
+                    reg.valid(e) ? reg.try_get<ECS::ScriptComponent>(e) : nullptr;
+                const bool stale = !sc || !it->second.behavior ||
+                                   it->second.behavior->Name() != sc->scriptName;
+                if (stale) {
+                    if (it->second.behavior) {
+                        it->second.behavior->OnDestroy();
+                    }
+                    it = m_Instances.erase(it);
+                } else {
+                    ++it;
+                }
+            }
+
+            // 2. 缺失实例化：按名查注册表（未知名警告——场景含未注册脚本时
+            //    弱前向兼容，跳过不影响其余实体）
+            const auto view = reg.view<ECS::ScriptComponent>();
+            for (auto [e, sc] : view.each()) {
+                const u32 bits = static_cast<u32>(entt::to_integral(e));
+                if (m_Instances.contains(bits) || sc.scriptName.empty()) {
+                    continue;
+                }
+                auto behavior = ScriptRegistry::Create(sc.scriptName);
+                if (!behavior) {
+                    ENGINE_WARN("Script '{}' not registered (entity {})",
+                                sc.scriptName, bits);
+                    continue;
+                }
+                behavior->Bind(m_Scene, e);
+
+                ScriptInstance inst;
+                inst.behavior = std::move(behavior);
+                inst.behavior->OnCreate(); // Unity Awake 语义：实例化即回调
+                inst.created = true;
+                m_Instances.emplace(bits, std::move(inst));
+            }
+        }
+
+    } // namespace Scripting
+} // namespace Engine

Engine/src/Serialization/SceneSerializer.cpp

@@ -343,6 +343,14 @@ namespace Engine::Serialization {
                 out << YAML::EndMap;
             }
 
+            // 脚本只存类名（注册表键）；未注册名字加载后运行时警告跳过
+            if (const auto* sc = reg.try_get<ECS::ScriptComponent>(e)) {
+                out << YAML::Key << "Script" << YAML::Value << YAML::BeginMap;
+                out << YAML::Key << "ScriptName" << YAML::Value
+                    << sc->scriptName;
+                out << YAML::EndMap;
+            }
+
             out << YAML::EndMap;   // Components
             out << YAML::EndMap;   // Entity
         }
@@ -628,6 +636,12 @@ namespace Engine::Serialization {
                 cc.stepHeight = n["StepHeight"].as<f32>(cc.stepHeight);
                 // 状态（速度/着地）由 PhysicsWorld 对账重建，不存
             }
+
+            // 脚本：只存类名；未注册名字由 ScriptRuntime 运行时警告跳过
+            if (const YAML::Node n = comps["Script"]) {
+                auto& sc = handle.AddComponent<ECS::ScriptComponent>();
+                sc.scriptName = n["ScriptName"].as<std::string>("");
+            }
         }
 
         // 加载在 OnImGuiRender 段，错过本帧 UpdateTransforms：