methinks there is oil involved in the roasting process that facilitates salt adhesion.(probably just the almond's own oil rising to the surface)
but i'm just guessing.
i would guess they are roasted, then tossed in salt while still hot.
but again, purely guesswork.
If you make a saturated brine, a very light spray and evaporation will leave a dusting of salt.
For saturated brine, I buy himalayan rock salt chunks from the animal produce fir 50c/lb, drop a large chunk in a pint jar and let it dissolve overnight.
As you use it, top up with water while ever there is solid salt in the jar.