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/Scripting/ScriptRuntime.cpp

@@ -22,9 +22,14 @@ namespace Engine {
             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)) {
+                const ECS::ScriptComponent* sc = reg.valid(e)
+                    ? reg.try_get<ECS::ScriptComponent>(e) : nullptr;
+                if (!sc) {
                     continue; // 延迟销毁队列里，下帧 Sync 清理
                 }
+                if (!sc->active) {
+                    continue; // 禁用 = 保留实例停 tick（Unity disable 语义）
+                }
                 if (!inst.created) {
                     inst.behavior->OnCreate();
                     inst.created = true;