fix bug where splitter filters were not taken over to blueprint

src/ui/BlueprintPanel.cpp

@@ -201,6 +201,16 @@ Blueprint BlueprintPanel::createBlueprintFromSelection() const
         bb.offset     = e.building->anchor - center;
         bb.recipeId   = e.building->recipeId;
         bb.shipLayout = e.building->shipLayout;
+        if (e.building->type == BuildingType::Splitter)
+        {
+            const std::optional<BeltSystem::SplitterInfo> info =
+                m_sim->belts().getSplitterInfo(e.building->anchor);
+            if (info.has_value())
+            {
+                bb.splitterFilterA = info->filterA;
+                bb.splitterFilterB = info->filterB;
+            }
+        }
         bp.buildings.push_back(bb);
     }
     return bp;

src/ui/GameWorldView.cpp

@@ -58,6 +58,19 @@
 namespace
 {
 
+// Keep only the filter entries whose item type is currently unlocked
+// (REQ-LOCK-UI-BLUEPRINT). An empty result means "accept all".
+std::vector<ItemType> filterUnlockedItems(const std::vector<ItemType>& filter,
+                                          const Simulation& sim)
+{
+    std::vector<ItemType> result;
+    for (const ItemType& item : filter)
+    {
+        if (sim.isItemUnlocked(item.id)) { result.push_back(item); }
+    }
+    return result;
+}
+
 Rotation rotateClockwise(Rotation r)
 {
     switch (r)
@@ -532,6 +545,18 @@ void GameWorldView::placeBlueprintAtTile(QPoint center)
         {
             m_sim->buildings().setShipLayout(id, *bb.shipLayout);
         }
+
+        if (bb.type == BuildingType::Splitter
+            && (!bb.splitterFilterA.empty() || !bb.splitterFilterB.empty()))
+        {
+            // The splitter is still a construction site, so the filters carry
+            // over when it finishes building (REQ-UI-BLUEPRINT-PLACE). Locked
+            // item types are dropped per REQ-LOCK-UI-BLUEPRINT.
+            m_sim->buildings().setSiteSplitterFilters(
+                id,
+                filterUnlockedItems(bb.splitterFilterA, *m_sim),
+                filterUnlockedItems(bb.splitterFilterB, *m_sim));
+        }
     }
 }