price per item is printed

test/export_test.dart

@@ -88,6 +88,7 @@ void main() {
         druckdauerMinuten: 60,
         gewichtGramm: 40,
         abfallGramm: 10,
+        gesamtpreis: 12.5,
         filamente: [
           const BauteilFilamentModel(
             filamentId: 'f1',
@@ -129,6 +130,7 @@ void main() {
       await controller.importData();
       expect(storage.tables, fixture());
       expect(home.materialien, ['PA12', 'PLA']);
+      expect(home.filamentIdsMitProfil, contains('f1'));
       expect(home.restgewicht(home.filamente.single), 950);
       expect(controller.hasError.value, isFalse);
     },
@@ -174,6 +176,23 @@ void main() {
     expect(storage.tables, fixture());
   });
 
+  test('Backup imports accept legacy parts without price and reject negative prices', () {
+    final legacy = fixture();
+    legacy[StorageKeys.bauteile]!.single.remove('gesamtpreis');
+    final decoded = BackupModel.decode(BackupModel(legacy).encode());
+    expect(
+      BauteilModel.fromJson(decoded.data[StorageKeys.bauteile]!.single)
+          .gesamtpreis,
+      isNull,
+    );
+    final invalid = fixture();
+    invalid[StorageKeys.bauteile]!.single['gesamtpreis'] = -1;
+    expect(
+      () => BackupModel.decode(BackupModel(invalid).encode()),
+      throwsFormatException,
+    );
+  });
+
   test('A failed import restores previously written tables', () async {
     storage.tables.addAll(fixture());
     files.source = BackupModel({for (final key in BackupModel.keys) key: []})