Allow to draw produced-item icons in recipe dialog and game world

src/ui/GameWorldView.h

@@ -13,6 +13,7 @@
 #include <QElapsedTimer>
 #include <QOpenGLWidget>
 #include <QPoint>
+#include <QPointF>
 #include <QRectF>
 #include <QTimer>
 #include <QVector2D>
@@ -51,6 +52,7 @@
 
 struct Command;
 struct ParsedReplay;
+class ItemIconCache;
 class ReplayPlayer;
 class Simulation;
 class QPainter;
@@ -128,6 +130,12 @@ private:
     void drawCopyConfigFeedback(QPainter& painter);
     void drawStations(QPainter& painter);
     void drawBeltItems(QPainter& painter);
+    // Draws a single item centered at widget-space `center`, spanning `halfPx` in
+    // each direction (a half-tile). Uses the item's icon when one exists
+    // (REQ-UI-ITEM-ICON), otherwise falls back to the colored square from
+    // visuals.toml. Shared by drawBeltItems and drawPortItems.
+    void drawWorldItem(QPainter& painter, const std::string& itemId,
+                       QPointF center, float halfPx);
     void drawDebris(QPainter& painter);
     void drawShips(QPainter& painter);
     void drawHpBar(QPainter& painter, qreal left, qreal top, qreal width,
@@ -296,6 +304,10 @@ private:
     };
     std::map<BuildingType, BuildingIconRenderers> m_buildingIcons;
 
+    // Per-item icon cache (REQ-UI-ITEM-ICON), loaded from <configDir>/../icons/items.
+    // Shared draw path for belt and port items; pixmaps are cached per target size.
+    std::unique_ptr<ItemIconCache> m_itemIcons;
+
     // Funnels all player input into the single Simulation::apply chokepoint.
     CommandManager m_commandManager;
     // A Reset command was enqueued; reset the view after the next drain applies it.