feat(ecs): per-component enable/disable + inspector rework

Add `active` flag to the 8 behavior components (Unity enabled / UE
SetActive semantics; structural Id/Name/Transform excluded). Consumers
skip disabled components: renderer (mesh/light/anim), primary camera
election, physics reconciliation (body/constraint/character destroyed
and rebuilt on toggle), scripts keep instance but stop ticking.

Inspector: component headers now carry an enable checkbox and a remove
button, Add-Component menu greys out attached entries, and conflict
hints added (RigidBody <-> CharacterController mutual exclusion, Joint
requires RigidBody, Animation requires MeshRenderer, unregistered
script name). Scenes persist Active per component (default true).

Engine/src/Renderer/SceneRenderer.cpp

@@ -328,6 +328,7 @@ namespace Engine
         u32 collectedCount = 0;
         scene.Each<TransformComponent, LightComponent>(
             [&](Entity, TransformComponent& t, LightComponent& light) {
+            if (!light.active) return; // 组件禁用 = 不参与光照
             if (collectedCount >= kMaxLights) return;
 
             auto& dst = collected[collectedCount++];
@@ -392,6 +393,7 @@ namespace Engine
         m_EntitySkinBase.clear();
         scene.Each<MeshRendererComponent, AnimationComponent>(
             [&](Entity entity, MeshRendererComponent& mr, AnimationComponent& anim) {
+                if (!anim.active) return; // 组件禁用 = 暂停采样（播放头不动）
                 const Model* model = assets.GetModel(mr.model);
                 if (!model || !model->HasAnimations()) return;
                 const auto& clips = model->GetClips();
@@ -513,6 +515,7 @@ namespace Engine
 
         scene.Each<TransformComponent, MeshRendererComponent>(
             [&](Entity entity, TransformComponent& t, MeshRendererComponent& mr) {
+                if (!mr.active) return; // 组件禁用 = 不渲染不拾取
                 Model* model = assets.GetModel(mr.model);
                 if (!model) return;