With halui.program.is-idle being an out pin, simple modifactions of the pin assignment should work:
Delete from above:
net prog-running not.0.in <= halui.program.is-idle
replace by:
net program.is-idle not.0.in
You can connect a HAL out pin to multiple IN pins, however, it must be within one signal name. The signal name ist the first part after the net command.