In a points ignition system, should the condenser(capacitor) be attached to the coil terminal or to the breaker points
TL;DR put it in the distributor housing, next to the points, where there's space for it and it's designed to go.

At the lowish frequencies associated with the main purpose of the capacitor, suppressing an arc at the points, there should not be too much difference between putting it at the points or the coil. However, to minimise the stray inductance in series with the points which the capacitor cannot control, it's best to minimise the loop area enclosed by the change of path between the points closed and points open current path, this is the loop that comprises the stray inductance.

When you look at what it also does for you, suppressing radio interference, it's best to minimise the loop area enclosed by the change of path between the points closed and points open current path, this is the loop that will radiate RF.