A project file, an .aep, a timeline document or a Lottie file could give a
layer a time stretch of 1e-300 %, 0 or 1e300 %. Layer and comp time divide
by it and the audio mix read about usize::MAX source samples for one block,
which overflowed or tried a huge allocation and aborted the app.
- limits::stretch brings a stretch within After Effects' range (±1 % to
±9900 %, Layer.stretch in the scripting guide), sign kept; 0 and NaN are
100 %. Opening a project file corrects each layer and says so; a stretch
written as null (NaN in an auto-save) now opens instead of failing.
- .aep import and Lottie import clamp and report the stretch; timeline
import clamps the clip speed and warns.
- layer.timeStretch refuses a non-number and more than 9900 %; the Time
Stretch dialog's ranges match.
- Layer::layer_time / comp_time and the audio mix use the clamped stretch,
so a value set in memory can't divide by zero or read without bound.
Fixes#3247
vangel76