UPDATE: I was just perusing an online seed catalog and came across this, which looks exactly like the fruits of my mystery plant:
At the end of the gardening season a few years ago I discovered a Solanum plant with bright red-orange fruits on the weed discard pile in our community garden. I collected the fruit, saved some seeds and grew out several plants in 2021. I haven’t been able to positively identify the species (or hybrid?) but when I tasted the juice and pulp I didn’t suffer any ill effects. The flavor, however, was very bland and I can’t see growing it as more than an ornamental curiosity. I grew them in approximately #3 pots and they didn’t get more than a foot tall.
Driftless Roots 