2007 Escalade ESV - Screech noise then engine shuts off at idle

I have an issue where our Escalade is now shutting off on us randomly at idle. When the engine shuts off, there is a loud screech noise just before it shuts off.

-Oil has always been well maintained and looks good.
-226,000 miles
-Serpentine belt is like new
-Power steering pulley is a little hard to spin and makes a weird noise when I spin it by hand. I’m not sure if that’s normal.
-Water pump pulley doesn’t spin too freely either and also has a noise when I spin it by hand.
-I hear an intermittent whistling noise when engine running that turns into a solid pulley whistling noise once warmed up.

My only thought so far is maybe a pulley is getting ready to seize and it has randomly seized up causing the engine to shut off at an idle? I didn’t think a pulley could make an engine shut off, I thought it would just smoke the belt but maybe at an idle it would? I don’t know what else to think right now.