lottie_animation_from_data uses 'key' as a cache key for parsed models.
All LottieIcon instances were created with key="", causing rlottie's
model cache to return the first loaded animation for all subsequent
requests. Only visible on Windows where rlottie cache is enabled by
default.
Fix: pass unique animPath as key to each LottieIcon constructor.
Also replaced fprintf(stderr) diag with GUI_INFO logging via
AnimTimer::logRegisteredIcons() in debug_ui.h.
Evgeny