feat: start working on sell

lib/data/repositories/owner_repository.dart

@@ -16,6 +16,22 @@ class OwnerRepository {
   final WebsocketClient _wsClient;
   late final StreamSubscription sub;
   List<Owner>? _cachedOwners;
+  Owner? _sectionOwner;
+
+  Future<Result<Owner>> get sectionOwner async {
+    if (_sectionOwner != null) {
+      return Result.ok(_sectionOwner!);
+    }
+    final result = await _apiClient.getSectionOwner();
+    switch (result) {
+      case Ok():
+        _sectionOwner = result.value;
+        break;
+      default:
+        break;
+    }
+    return result;
+  }
 
   /// Adds an [Owner] to the database, and gets the resulting [Owner].
   Future<Result<Owner>> addOwner(