Runs the real worker against the real @turf modules, because what broke twice was
never the geometry: the worker script and the turf packages sit in sibling
directories of the bundle that a bare require() cannot reach (3249362), and the
first fix doubled the programs/server prefix so nothing resolved (570cb49).
The last test is the reason the worker exists at all: timers keep firing while a
120-circle union computes. Revert fbb746f and it fails.
