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

src/ui/RecipeSelectionDialog.h

@@ -20,6 +20,10 @@ struct RecipeSelectionOption
     std::string id;
     QString     caption;
     QString     tooltip;
+    // Id of the item whose icon is shown on the option button (REQ-UI-RECIPE-ICON);
+    // empty for the "(None)" option and for Shipyard schematics, which keep their
+    // caption. When set but no icon file exists, the button falls back to the caption.
+    std::string iconItemId;
 };
 
 // Builds the lock-aware list of selectable options for a production building
@@ -39,8 +43,12 @@ class RecipeSelectionDialog : public QDialog
     Q_OBJECT
 
 public:
+    // itemIconDir is the directory holding per-item icon SVGs (REQ-UI-ITEM-ICON);
+    // used to render recipe options icon-only (REQ-UI-RECIPE-ICON). Options whose
+    // item has no icon file fall back to their caption text.
     RecipeSelectionDialog(const std::vector<RecipeSelectionOption>& options,
-                          const QString& title, QWidget* parent = nullptr);
+                          const QString& title, const QString& itemIconDir,
+                          QWidget* parent = nullptr);
 
     std::optional<std::string> getChosenId() const;