Fix .sea files not being listed in scenario index (#23013)

distribution/changelog.txt

@@ -6,6 +6,7 @@
 - Fix: [#22918] Zooming with keyboard moves the view off centre.
 - Fix: [#22921] Wooden RollerCoaster flat to steep railings appear in front of track in front of them.
 - Fix: [#22962] Fuzzy horizontal-to-vertical line transitions in charts.
+- Fix: [#23009] Scenarios from RCT Classic (.sea files) are not included in the scenario index.
 
 0.4.15 (2024-10-06)
 ------------------------------------------------------------------------

src/openrct2/scenario/ScenarioRepository.cpp

@@ -209,15 +209,24 @@ private:
             std::string extension = Path::GetExtension(path);
 
             if (String::IEquals(extension, ".park"))
+            {
                 importer = ParkImporter::CreateParkFile(objRepository);
+                importer->LoadScenario(path, true);
+            }
             else if (String::IEquals(extension, ".sc4"))
+            {
                 importer = ParkImporter::CreateS4();
+                importer->LoadScenario(path, true);
+            }
             else
+            {
                 importer = ParkImporter::CreateS6(objRepository);
+                auto stream = GetStreamFromRCT2Scenario(path);
+                importer->LoadFromStream(stream.get(), true);
+            }
 
             if (importer)
             {
-                importer->LoadScenario(path, true);
                 if (importer->GetDetails(entry))
                 {
                     entry->Path = path;