- AnimTimer::shutdown(): stop QTimer, clear m_icons before icon destruction
- ~MainWindow: AnimTimer::shutdown() -> cleanupAnimations() (correct order)
- main: replace ExitProcess with TerminateProcess(GetCurrentProcess,0)
TerminateProcess skips DLL_PROCESS_DETACH, avoiding libwinpthread
pthread_join hang on rlottie/miniaudio threads.
rlottie C API has no global shutdown - internal RleTaskScheduler threads
cannot be stopped through public API. Same for miniaudio WASAPI threads.
All owned resources already freed before TerminateProcess.