Update. I went through the bleed process Scotty recommended. I took the rad cap off, started the car (I watched for bubbles too, in case a head gasket issue had yet to manifest, but no bubbles or level rising came... yet) and I let the car warm up. I kept checking the top hose to see when the thermostat opened, which it did at 180, then I let the car heat up until the fans came on at 212, and then before i could open the bleed screw, coolant suddenly started gushing and gurgling out of the radiator, white with bubbles, and then suddenly stopped. About a quart came out. I filled it up again and waited, but it didn't happen again, and the temp went back down to about 206 and the fans turned off. So then I bled it from the bleeder and only coolant came out. No bubbles.
I watched the temp for a few minutes while the car idled. It just kept bouncing back and forth between 203 and 212, when the fans would kick on.
So what happened here? Did I find my air pocket, or did the heat just boil my coolant for a few moments? Is 203-212 normal for idle?