static void RunCutsceneChecks(EditorApp& app) {
    Check(app.LoadLevel("../assets/map.dat"), "cutscene test starts from legacy map");
    app.playerStartAngle = 508; app.playerStartY = 3;
    app.cutscene.flags = CUTSCENE_AUTOPLAY;
    app.cutscene.strings = {"Привет, мир!", "quiet.wav"};
    app.cutscene.events = {
        {0,OP_MOVE_CAM_TO,0,288,160,4}, {0,OP_PAN_CAM_TO,0,4,4,0},
        {0,OP_FADE_SCREEN,0,16,4,0}, {0,OP_SHOW_SUBTITLE,0,0,0,0},
        {0,OP_PLAY_SOUND,0,1,0,0}, {1,OP_WAIT,0,2,0,0},
        {2,OP_HIDE_SUBTITLE,0,0,0,0}, {4,OP_FADE_SCREEN,0,0,4,0}, {8,OP_END,0,0,0,0}
    };
    Check(app.SaveLevel("../assets/scene.dat"), "save v4 cutscene, Russian text and sound reference");
    BinaryLevel level; std::string error;
    Check(ReadLevelFile("../assets/scene.dat",level,error) && level.header.version == MAP_FORMAT_VERSION && level.cutscene.events.size() == 9 &&
        level.cutscene.strings[0] == "Привет, мир!" && level.cutscene.flags == CUTSCENE_AUTOPLAY,
        "v4 track round trip retains UTF8 and autoplay");
    std::string encoded;
    Check(CutsceneEncode("Привет, мир!",encoded) && encoded.size() == 12 && static_cast<unsigned char>(encoded[0]) == 0xCF,
        "Russian subtitles use the runtime CP1251 font");
    Check(!CutsceneEncode("😀",encoded), "unrepresentable subtitle is rejected");
    CutscenePreview preview;
    preview.Start(160,224,508);
    std::ofstream trace("../assets/cutscene_reference.bin",std::ios::binary);
    int audioCount = 0;
    for (int tick=0;tick<=8;++tick) {
        preview.Step(app.cutscene,[&](int id,bool loop) { if(id==1 && !loop) ++audioCount; });
        int state[6] = {preview.x,preview.y,preview.angle,preview.fade,preview.subtitle,preview.active?1:0};
        trace.write(reinterpret_cast<const char*>(state),sizeof(state));
        if (tick==2) Check(preview.x==224 && preview.y==192 && preview.angle==0 && preview.fade==8 && preview.subtitle==0,
            "preview interpolates signed movement, shortest angle, fade and wait");
        if (tick==3) Check(preview.subtitle==-1, "wait delays a following hide command until its deadline");
    }
    trace.close();
    Check(preview.x==288 && preview.y==160 && preview.angle==4 && !preview.active && preview.fade==0 && audioCount==1,
        "preview reaches exact targets and stops cleanly");
    auto invalid = app.cutscene;
    invalid.events[0].dataId=3601;
    Check(!ValidateCutscene(invalid,&app.map[0][0],app.transitions.size(),error), "oversized camera duration rejected");
    invalid=app.cutscene;invalid.events[3].paramA=99;
    Check(!ValidateCutscene(invalid,&app.map[0][0],app.transitions.size(),error), "invalid string reference rejected");
    invalid=app.cutscene;invalid.events.pop_back();
    Check(!ValidateCutscene(invalid,&app.map[0][0],app.transitions.size(),error), "missing end marker rejected");
    invalid=app.cutscene;invalid.events[0].paramA=0;invalid.events[0].paramB=0;
    Check(!ValidateCutscene(invalid,&app.map[0][0],app.transitions.size(),error), "camera point in a wall rejected");
    for (const char* file : {"scene_badop.dat","scene_badref.dat","scene_badtext.dat","scene_badorder.dat","scene_badflags.dat","scene_noend.dat"}) {
        Check(!app.LoadLevel(std::string("../assets/")+file) && app.cutscene.events.size()==9,
            "malformed cutscene load preserves editor track");
    }
    std::string start, engine;
    Check(app.PreparePlaytest(start,engine) && start=="assets\\scene.dat", "F5 packages v4 track and referenced WAV");
    app.CleanupPlaytest();
    app.cutscene.strings[1]="absent.wav";start.clear();engine.clear();
    Check(!app.PreparePlaytest(start,engine), "F5 rejects missing cutscene audio before launch");
    app.CleanupPlaytest();
    app.LoadLevel("../assets/map.dat");
    Check(app.cutscene.events.empty() && app.cutscene.strings.empty(), "legacy map clears previous track");
    app.AddCutsceneEvent(OP_MOVE_CAM_TO);
    Check(app.cutscene.events.size()==2 && app.placeCameraPoint, "timeline camera button inserts an end marker and enables map placement");
    app.Undo();Check(app.cutscene.events.empty(), "undo includes cutscene commands");
    app.Redo();Check(app.cutscene.events.size()==2, "redo restores cutscene commands");
    app.cutscene = {};app.selectedCutsceneEvent=-1;
    for(int i=0;i<40;++i) { app.AddCutsceneEvent(OP_SHOW_SUBTITLE);app.DeleteCutsceneEvent(); }
    Check(app.cutscene.strings.empty(), "deleting commands reclaims string pool slots");
    app.AddCutsceneEvent(OP_CHANGE_SUBLEVEL);
    app.SetCell(4,2,CELL_EMPTY);
    Check(std::none_of(app.cutscene.events.begin(),app.cutscene.events.end(),[](const auto& e){return e.opCode==OP_CHANGE_SUBLEVEL;}),
        "removing a portal repairs cutscene transition references");
    app.LoadLevel("../assets/scene.dat");app.showCutsceneTimeline=true;
    ImGui::CreateContext();
    auto& io=ImGui::GetIO();io.DisplaySize=ImVec2(1360,840);io.DeltaTime=1.0f/60;io.IniFilename=nullptr;
    unsigned char* pixels;int w,h;io.Fonts->GetTexDataAsRGBA32(&pixels,&w,&h);
    ImGui::NewFrame();app.RenderUI();ImGui::Render();
    Check(ImGui::GetDrawData()->TotalVtxCount>0,"editor timeline renders without a native window");
    io.AddKeyEvent(ImGuiKey_F5,true);
    ImGui::NewFrame(); io.WantCaptureKeyboard=true; io.WantTextInput=true;
    app.HandleHotkeys();
    Check(app.isEngineRunning,"F5 launches even when ImGui captures keyboard input");
    ImGui::Render();
    if(app.hEngineProcess) WaitForSingleObject(app.hEngineProcess,5000);
    app.CheckPlaytestProcess();
    io.AddKeyEvent(ImGuiKey_F5,false); io.AddKeyEvent(ImGuiKey_F6,true);
    ImGui::NewFrame(); io.WantCaptureKeyboard=true; io.WantTextInput=true;
    app.HandleHotkeys();
    Check(!app.showCutsceneTimeline,"F6 remains available while a text widget owns focus");
    ImGui::Render();
    ImGui::DestroyContext();
    app.showCutsceneTimeline=false;
}