feat(ui): Background (rename Bg) com RoundedBox + borda na cor da variante

- Bg -> Background (nome descritivo). - RefreshUIStyle: monta o brush do Background como RoundedBox quando bRoundedBackground (default true): TintColor=BgNormal, OutlineSettings(CornerRadii=Button.CornerRadius, Color=BorderNormal, Width=Button.BorderWidth, RoundingType=FixedRadius). 'So borda com a cor' = variante com BgNormal transparente + BorderNormal na cor (data-driven, como o Hyper). bRoundedBackground=false -> caixa reta. Compila OK.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Source/ZMMO/Game/UI/Widgets/UIButton_Base.cpp

@@ -5,6 +5,7 @@
 #include "Engine/World.h"
 #include "TimerManager.h"
 #include "Components/Border.h"
+#include "Styling/SlateBrush.h"
 #include "Components/TextBlock.h"
 #include "Components/Image.h"
 #include "Components/SizeBox.h"
@@ -165,9 +166,31 @@ void UUIButton_Base::RefreshUIStyle()
 	const FUIStyle& ActiveStyle = ResolveActiveStyle(this, Fallback);
 	const FUIStyleButtonVariant& VariantStyle = ResolveVariant(ActiveStyle.Button);
 
-	if (Bg)
+	if (Background)
 	{
-		Bg->SetBrushColor(VariantStyle.BgNormal);
+		// Fundo + borda na cor da variante. RoundedBox dá cantos arredondados
+		// e a borda colorida (BorderNormal) — "só borda" = BgNormal transparente.
+		FSlateBrush Brush = Background->Background;
+		Brush.TintColor = FSlateColor(VariantStyle.BgNormal);
+		if (bRoundedBackground)
+		{
+			const float R = ActiveStyle.Button.CornerRadius;
+			Brush.DrawAs = ESlateBrushDrawType::RoundedBox;
+			Brush.OutlineSettings = FSlateBrushOutlineSettings(
+				FVector4(R, R, R, R),
+				FSlateColor(VariantStyle.BorderNormal),
+				ActiveStyle.Button.BorderWidth);
+			Brush.OutlineSettings.RoundingType = ESlateBrushRoundingType::FixedRadius;
+		}
+		else
+		{
+			Brush.DrawAs = ESlateBrushDrawType::Box;
+			Brush.OutlineSettings = FSlateBrushOutlineSettings(
+				FVector4(0, 0, 0, 0),
+				FSlateColor(VariantStyle.BorderNormal),
+				ActiveStyle.Button.BorderWidth);
+		}
+		Background->SetBrush(Brush);
 	}
 	if (ButtonText)
 	{

Source/ZMMO/Game/UI/Widgets/UIButton_Base.h

@@ -62,6 +62,11 @@ public:
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Text Style")
 	bool bAutoSizeText = true;
 
+	/** Arredonda o Background (RoundedBox) e desenha a borda na cor da
+	 *  variante. Desligado = caixa reta. Raio/largura vêm de FUIStyleButton. */
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Button")
+	bool bRoundedBackground = true;
+
 	// ---- Number Text ----
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Number Text")
 	bool bShowNumberText = false;
@@ -176,7 +181,7 @@ protected:
 
 	/** Fundo temável (nossa adição sobre o Hyper, p/ FUIStyle). */
 	UPROPERTY(meta = (BindWidgetOptional))
-	TObjectPtr<UBorder> Bg;
+	TObjectPtr<UBorder> Background;
 
 private:
 	void StartDeactivateTimeout();