fix bug where splitter filters were not taken over to blueprint

src/test/BlueprintSerializerTest.cpp

@@ -10,6 +10,7 @@
 #include "Blueprint.h"
 #include "BlueprintSerializer.h"
 #include "BuildingType.h"
+#include "ItemType.h"
 #include "Rotation.h"
 #include "ShipLayout.h"
 
@@ -263,3 +264,42 @@ TEST_CASE("BlueprintSerializer: shipyard with empty modules list round-trips", "
     REQUIRE(loaded[0].buildings[0].shipLayout.has_value());
     REQUIRE(loaded[0].buildings[0].shipLayout->placedModules.empty());
 }
+
+// ---------------------------------------------------------------------------
+// Splitter output filters round-trip through TOML serialization
+// (REQ-UI-BLUEPRINT-STORAGE).
+// ---------------------------------------------------------------------------
+
+TEST_CASE("BlueprintSerializer: splitter output filters round-trip", "[serializer]")
+{
+    BlueprintBuilding splitter =
+        makeBuilding(BuildingType::Splitter, Rotation::East, QPoint(0, 0));
+    splitter.splitterFilterA = { ItemType{"iron_ore"}, ItemType{"copper_ore"} };
+    splitter.splitterFilterB = { ItemType{"scrap"} };
+
+    const Blueprint original = makeBlueprintWith({ splitter }, "Sorter");
+    const std::string toml = BlueprintSerializer::serialize({ original });
+    const std::vector<Blueprint> loaded = BlueprintSerializer::deserialize(toml);
+
+    REQUIRE(loaded.size() == 1);
+    REQUIRE(loaded[0].buildings.size() == 1);
+
+    const BlueprintBuilding& b = loaded[0].buildings[0];
+    REQUIRE(b.splitterFilterA
+            == std::vector<ItemType>{ ItemType{"iron_ore"}, ItemType{"copper_ore"} });
+    REQUIRE(b.splitterFilterB == std::vector<ItemType>{ ItemType{"scrap"} });
+}
+
+TEST_CASE("BlueprintSerializer: splitter with no filters round-trips empty", "[serializer]")
+{
+    const Blueprint original = makeBlueprintWith(
+        { makeBuilding(BuildingType::Splitter, Rotation::East, QPoint(0, 0)) }, "Open");
+
+    const std::string toml = BlueprintSerializer::serialize({ original });
+    const std::vector<Blueprint> loaded = BlueprintSerializer::deserialize(toml);
+
+    REQUIRE(loaded.size() == 1);
+    REQUIRE(loaded[0].buildings.size() == 1);
+    REQUIRE(loaded[0].buildings[0].splitterFilterA.empty());
+    REQUIRE(loaded[0].buildings[0].splitterFilterB.empty());
+}