feat(ecs): add entity type separation and creature limits

Replace generic entity creation with typed creatures and items. Rename `add_entity` to `add_creature`, enforce per-player creature cap, and track entity/creature totals for metrics. Expose run mode to dev panel and show new counts.

include/Cubed/gameplay/ecs/entity.hpp

@@ -3,9 +3,12 @@
 namespace Cubed {
 using EntityID = uint64_t;
 
+enum class EntityType { CREATURE, ITEM };
+
 struct Entity {
     EntityID id;
-    explicit Entity(EntityID id) : id(id) {}
+    EntityType type;
+    Entity(EntityID id, EntityType type) : id(id), type(type) {}
 };
 
 } // namespace Cubed

include/Cubed/gameplay/server_entity_manager.hpp

@@ -12,15 +12,20 @@ class ServerWorld;
 class Session;
 class ServerEntityManager {
 public:
+    static constexpr size_t PER_CREATURE_LIMITS = 100;
+
     ServerEntityManager(ServerWorld& world);
 
     void init();
     void update();
-    // not thread safe
-    void add_entity(std::string_view name, const glm::vec3& world_pos);
+    void add_creature(std::string_view name, const glm::vec3& world_pos);
     void destory(EntityID id);
     void handle_player_login(std::shared_ptr<Session> session);
 
+    size_t max_creature_sum() const;
+    size_t creature_sum() const;
+    size_t entity_sum() const;
+
 private:
     enum class Command { CREATE, SEND_ALL_ENTITIES, DESTORY };
     struct EntityCreateElement {
@@ -43,6 +48,8 @@ private:
         std::variant<std::shared_ptr<Session>, EntityCreateElement, EntityID>;
     using TaskPair = std::pair<Command, TaskElement>;
     ServerWorld& m_world;
+    std::atomic<size_t> m_creature_sum{0};
+    std::atomic<size_t> m_entity_sum{0};
     tbb::concurrent_queue<TaskPair> m_tasks;
     entt::registry m_registry;
     EntityID m_next = 0;

include/Cubed/gameplay/server_world.hpp

@@ -98,6 +98,8 @@ public:
     uint32_t get_chunk_ref_count(const glm::vec3& pos) const;
     ServerEntityManager& entity_manager();
     std::shared_ptr<ThreadPool> get_compute_pool();
+    size_t player_sum() const;
+
     int get_block(const glm::ivec3& block_pos) const override;
     bool is_solid(const glm::ivec3& block_pos) const override;
     bool can_pass_block(const glm::ivec3& block_pos) const override;

include/Cubed/scene/world_scene.hpp

@@ -42,6 +42,8 @@ public:
 
     bool is_recording() const;
 
+    RunMode runmode() const;
+
 private:
     enum class PauseUI { PAUSE_MENU, INVENTORY };
     SceneManager& m_scene_manager;
@@ -61,6 +63,7 @@ private:
     ErrorUI m_error_ui;
     const Argument& m_argument;
     VoiceInputType m_input_type;
+    RunMode m_runmode = RunMode::HYBRID;
     bool handle_mouse_move_event(const MouseMoveEvent& e) override;
     bool handle_mouse_button_event(const MouseButtonEvent& e) override;
     bool handle_window_resize_event(const WindowResizeEvent& e) override;