修改场景实体查询为unordered_set存储，提升查询效率, 修改Physics的SyncScene也为unordered_set

Engine/src/ECS/Scene.cpp

@@ -17,21 +17,30 @@ namespace Engine::ECS {
     {
         Entity e = m_Registry.create();
         // 出生即有：UUID（稳定身份）+ Transform（空间存在性，Unity 语义）
-        m_Registry.emplace<IdComponent>(e, IdComponent{UUID::New()});
+        const auto& id = m_Registry.emplace<IdComponent>(e, IdComponent{UUID::New()});
         m_Registry.emplace<TransformComponent>(e);
         m_Registry.emplace<NameComponent>(e, NameComponent{std::move(name)});
+        m_UUIDToEntity.emplace(id.uuid, e);
         return EntityHandle{this, e};
     }
 
     Entity Scene::FindEntityByUUID(UUID uuid)
     {
         if (!uuid.Valid()) return entt::null;
+        const auto it = m_UUIDToEntity.find(uuid);
+        // 防御：实体可能已销毁（map 仍残留过时项），二次校验 valid
+        if (it == m_UUIDToEntity.end() || !m_Registry.valid(it->second)) {
+            return entt::null;
+        }
+        return it->second;
+    }
 
-        Entity found = entt::null;
-        m_Registry.view<IdComponent>().each([&](Entity e, IdComponent& id) {
-            if (found == entt::null && id.uuid == uuid) found = e;
-        });
-        return found;
+    void Scene::RebuildUuidIndex() {
+        m_UUIDToEntity.clear();
+        m_Registry.view<IdComponent>().each(
+            [&](Entity e, const IdComponent& id) {
+                m_UUIDToEntity.emplace(id.uuid, e);
+            });
     }
 
     void Scene::DestroyEntity(Entity e)
@@ -70,6 +79,12 @@ namespace Engine::ECS {
                     std::remove(siblings.begin(), siblings.end(), e),
                     siblings.end());
             }
+
+            // 销毁前先从 UUID 索引摘掉（销毁后实体不可访问）
+            if (const auto* id = m_Registry.try_get<IdComponent>(e)) {
+                m_UUIDToEntity.erase(id->uuid);
+            }
+
             m_Registry.destroy(e);   // entt 自动回收槽位并递增版本号
         }
         m_PendingDestroy.clear();
@@ -81,6 +96,7 @@ namespace Engine::ECS {
         //（registry.clear() 后队列里的句柄全部失效，直接丢弃即可）
         m_PendingDestroy.clear();
         m_Registry.clear();
+        m_UUIDToEntity.clear();
     }
 
     EntityHandle Scene::GetEntityHandle(Entity e)

Engine/src/Physics/PhysicsWorld.cpp

@@ -343,7 +343,7 @@ namespace Engine {
     void PhysicsWorld::SyncScene() {
         auto &reg = m_Scene.GetRegistry();
         auto &bi = m_System->GetBodyInterface();
-        std::vector<u32> invalidated; // 本帧销毁/重建 body → 约束失效传染
+        std::unordered_set<u32> invalidated; // 本帧销毁/重建 body → 约束失效传染
 
         // 1. 孤儿清理：实体销毁 / 组件被移除 → 移除 body
         for (auto it = m_Bodies.begin(); it != m_Bodies.end();) {
@@ -353,7 +353,7 @@ namespace Engine {
                 bi.RemoveBody(it->second.id);
                 bi.DestroyBody(it->second.id);
                 m_BodyToEntity.erase(it->second.id.GetIndexAndSequenceNumber());
-                invalidated.push_back(it->first);
+                invalidated.insert(it->first);
                 it = m_Bodies.erase(it);
             } else {
                 ++it;
@@ -373,7 +373,7 @@ namespace Engine {
                     bi.DestroyBody(found->second.id);
                     m_BodyToEntity.erase(found->second.id.GetIndexAndSequenceNumber());
                     m_Bodies.erase(found);
-                    invalidated.push_back(bits);
+                    invalidated.insert(bits);
                 }
                 rb.bodyValid = false;
                 continue;
@@ -385,7 +385,7 @@ namespace Engine {
                     bi.DestroyBody(found->second.id);
                     m_BodyToEntity.erase(found->second.id.GetIndexAndSequenceNumber());
                     m_Bodies.erase(found);
-                    invalidated.push_back(bits);
+                    invalidated.insert(bits);
                 }
                 CreateBody(bits, rb, tr);
                 continue;
@@ -407,7 +407,7 @@ namespace Engine {
                 bi.DestroyBody(rec.id);
                 m_BodyToEntity.erase(found->second.id.GetIndexAndSequenceNumber());
                 m_Bodies.erase(found);
-                invalidated.push_back(bits);
+                invalidated.insert(bits);
                 rb.bodyValid = false;
                 CreateBody(bits, rb, tr);
                 continue;
@@ -456,11 +456,10 @@ namespace Engine {
 
     // ---- 约束对账 ----
 
-    void PhysicsWorld::SyncConstraints(const std::vector<u32> &invalidated) {
+    void PhysicsWorld::SyncConstraints(const std::unordered_set<u32> &invalidated) {
         auto &reg = m_Scene.GetRegistry();
-        const auto tainted = [&invalidated](u32 bits) {
-            return std::find(invalidated.begin(), invalidated.end(), bits)
-                   != invalidated.end();
+        const auto tainted = [&invalidated](const u32 bits) {
+                   return invalidated.count(bits);
         };
 
         // 1. owner 实体/组件没了（或被禁用），或任一端 body 本帧被销毁/重建 → 移除
@@ -901,6 +900,7 @@ namespace Engine {
         rb.bodyValid = true;
     }
 
+
     void PhysicsWorld::RemoveBody(const u32 entityBits) {
         const auto found = m_Bodies.find(entityBits);
         if (found == m_Bodies.end()) return;

Engine/src/Serialization/SceneSerializer.cpp

@@ -767,6 +767,10 @@ namespace Engine::Serialization {
         // 显式补算，否则首帧 World = 单位阵
         scene.UpdateTransforms();
 
+        // 序列化加载绕过了 CreateEntity 的 UUID 增量维护（565 行直接覆盖
+        // IdComponent.uuid），全量重建一次索引，否则 FindEntityByUUID 会全失效
+        scene.RebuildUuidIndex();
+
         ENGINE_INFO("SceneSerializer: loaded {} entities from '{}'",
                     parsed.size(), sourceName);
         return true;