refactor(ui): move scale property to subclasses and fix resize event handling

Remove scale from base Widget class and add per-type set_scale/scale methods to Button, Image, and Label. Dispatch separate WindowResizeEvent alongside existing FrameBufferResizeEvent. Correct centering calculations from `+` to `-` in main menu and world UI managers.

include/Cubed/ui/button.hpp

@@ -24,10 +24,10 @@ public:
 
     Widget& set_position(const glm::vec2& pos) override;
     Widget& set_position(float x, float y) override;
-    Widget& set_scale(float scale) override;
+    Button& set_scale(float scale);
     float width() const override;
     float height() const override;
-
+    float scale() const;
     template <typename F> Button& set_clicked(F&& f) {
         m_clicked = std::forward<F>(f);
         return *this;

include/Cubed/ui/image.hpp

@@ -16,6 +16,8 @@ public:
     float width() const override;
     float height() const override;
     const Texture* texture() const;
+    Image& set_scale(float scale);
+    float scale() const;
 
 private:
     const Texture* m_texture = nullptr;

include/Cubed/ui/label.hpp

@@ -17,6 +17,7 @@ public:
     Label& set_text(std::string_view text);
 
     Label& set_color(Color color);
+    Label& set_scale(float scale);
     virtual void update(float dt) override;
     virtual void render(Renderer& renderer) override;
 
@@ -28,6 +29,7 @@ public:
     float height() const override;
     float offset_x() const;
     float offset_y() const;
+    float scale() const;
 
 protected:
     virtual void on_update(float dt) override;
@@ -40,6 +42,7 @@ private:
     float m_real_height = 0.0f;
     float m_offset_x = 0.0f;
     float m_offset_y = 0.0f;
+    float m_scale = 1.0f;
     void update_vertices();
 };
 } // namespace Cubed

include/Cubed/ui/widget.hpp

@@ -18,11 +18,10 @@ public:
     virtual const std::string& id() const;
     virtual Widget& set_position(const glm::vec2& pos);
     virtual Widget& set_position(float x, float y);
-    virtual Widget& set_scale(float scale);
+    // Returns the final display size
     virtual float width() const;
     virtual float height() const;
     virtual const glm::vec2& pos() const;
-    virtual float scale() const;
 
     virtual bool handle_key_event(const KeyEvent& e);
     virtual bool handle_mouse_button_event(const MouseButtonEvent& e);
@@ -41,7 +40,6 @@ protected:
     virtual void on_update(float dt);
     virtual void on_render(Renderer& renderer);
     std::string m_id;
-    float m_scale = 1.0f;
     // Center is at the top-left corner, position is at the top-left corner
     glm::vec2 m_pos{0.0f, 0.0f};