give the selection cards their own parts instead of label blobs

src/ui/selection/RecipeSummaryRow.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include <QWidget>
+
+class ItemIconCache;
+class QHBoxLayout;
+
+// What one production cycle does, on a line: each input item with its per-cycle amount,
+// an arrow, each output with its amount, and the cycle time
+// (REQ-UI-RECIPE-SUMMARY). It restates the selected recipe without the player having to
+// open the selection dialog, and it is the panel's only display of the cycle time.
+class RecipeSummaryRow : public QWidget
+{
+    Q_OBJECT
+
+public:
+    struct Amount
+    {
+        std::string itemId;
+        int         amount = 0;
+
+        bool operator==(const Amount& other) const
+        {
+            return itemId == other.itemId && amount == other.amount;
+        }
+    };
+
+    // itemIcons is the window-wide per-item icon cache (REQ-UI-ITEM-ICON); an item with
+    // no icon file falls back to its id. Not owned.
+    explicit RecipeSummaryRow(ItemIconCache* itemIcons, QWidget* parent = nullptr);
+
+    // Hides the row when there is nothing selected to produce, which is how a building
+    // with no recipe shows no summary at all.
+    void setSummary(const std::vector<Amount>& inputs,
+                    const std::vector<Amount>& outputs, double durationSeconds);
+
+private:
+    void rebuild(const std::vector<Amount>& inputs, const std::vector<Amount>& outputs,
+                 double durationSeconds);
+    void addAmounts(const std::vector<Amount>& amounts);
+
+    ItemIconCache*      m_itemIcons;
+    QHBoxLayout*        m_layout;
+    // What the row currently shows, so a refresh at tick rate rebuilds it only when the
+    // recipe actually changed.
+    std::vector<Amount> m_inputs;
+    std::vector<Amount> m_outputs;
+    double              m_durationSeconds = -1.0;
+};