What I thought was power steering fluid is actually the brake fluid pooling up (see pic)
The leak is coming from the underside of the cloth braided line that runs between the reservoir and into the firewall (red arrow) -- I can squeeze it and feel liquid coming out. Explains why the brake fluid indicator came on and stayed on this afternoon.

How hard of a fix is this? My first thought is to grab a hose clamp, but I don't know if the split is too wide (or where it is exactly with the soggy fabric in the way).