explain an item wherever the UI names one

Every display naming an item now shows that item's production tooltip, not
only the selection panel's chips: the header block stock, the total cost of
a building multi-selection, the remaining scrap of a debris selection, the
icons of every recipe summary, and a blueprint card's cost.

ItemTooltip moves out of the selection panel and takes an
ItemTooltipContext of its own -- an item is named all over the UI, and the
panel's context carries visuals and a debug flag no tooltip reads. A
recipe line wraps each icon with its amount so the pair can be pointed at
as one statement, and attaches tooltips only where asked: a module button
and the item tooltip itself draw the same line and stay silent.

Hover only wherever the display sits on something the player clicks, whose
click is not free to explain. Note that a recipe line on an option button
can no longer be transparent to the mouse -- Qt never looks inside a
transparent widget for the cursor -- so it relies on press propagation to
keep picking the option.

The header block stock loses world.building_blocks_tooltip, showing what
every other block icon shows instead. The Expand button keeps no tooltip:
its cost is painted into its face with nowhere to hang one, and the button
is due to be removed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ne3mejABZoLWKLh8fgpM3x

src/ui/ShipLayoutDialog.h

@@ -9,6 +9,7 @@
 #include <QPoint>
 
 #include "GameConfig.h"
+#include "ItemTooltipContext.h"
 #include "ModalDialog.h"
 #include "Rotation.h"
 #include "ShipLayout.h"
@@ -25,15 +26,16 @@ class ShipLayoutDialog : public ModalDialog
     Q_OBJECT
 
 public:
-    // itemIcons draws what each module costs and what the layout costs in total
-    // (REQ-MOD-UI-DIALOG, REQ-MOD-UI-STATS-PANEL). Not owned.
-    ShipLayoutDialog(const GameConfig* config,
-                     const std::string& shipId,
+    // The context's item cache draws what each module costs and what the layout costs in
+    // total (REQ-MOD-UI-DIALOG, REQ-MOD-UI-STATS-PANEL), and the rest of it lets the
+    // build cost explain the items it names (REQ-UI-ITEM-VALUE-TOOLTIP). Nothing in it is
+    // owned.
+    ShipLayoutDialog(const std::string& shipId,
                      const ShipLayoutConfig& currentLayout,
                      std::vector<ShipLayoutBlueprint>& allBlueprints,
                      std::set<std::string> unlockedModuleIds,
                      bool debugDraw,
-                     ItemIconCache* itemIcons,
+                     const ItemTooltipContext& context,
                      QWidget* parent = nullptr);
 
     std::optional<ShipLayoutConfig> getResult() const;
@@ -78,6 +80,7 @@ private:
     std::vector<std::string> rotatedMask(const ModuleDef& def, Rotation rotation) const;
     void loadLayoutBlueprint(const std::vector<PlacedModule>& modules);
 
+    ItemTooltipContext m_context;
     const GameConfig* m_config;
     ItemIconCache* m_itemIcons;
     std::string m_shipId;