Leareth makes artifacts. He does occasional sweeps of the city for unexpected magic; he checks in about whether he ought to ward any additional storage areas they've started using. He finishes the food-preservation set, starts on the much larger and higher-powered camp wards. He eats, sleeps for a while, keeps going.
He's not going to have time for anything too complicated, here, but the fact that osanwë can interface with his kind of magic enough for the Quendi to control the wards themselves means he can put in a few options. As a default, they'll detect approaching magic, trigger an alarm if a Maiar-sized magic source tries to cross them, except Huan who he can key into the wards now; he'll ask Nelyafinwë about any other approved Maiar who are accompanying them. That part is low-powered; he can fully power the wards now, and they'll run for a week before they need maintenance.
In an emergency, a simple osanwë command from Nelyafinwë, or from someone else he trusts and wants Leareth to key in as well, will raise an impassible physical and magical barrier around the warded area. Well, probably not impassible to a god, but breaking it down won't be quick or silent even for Melkor. The emergency level is, unsurprisingly, very costly in terms of mage-energy; it'll run the wards down in less than twelve hours. Hopefully any emergency won't last that long.
:Nelyafinwë, is there somebody I might speak to who is an expert in your existing magical artifacts?: he asks eventually. :I had the sense Macalaurë is knowledgeable here. There may not be time to do it now, but I wished to investigate whether it is possible to directly tie the two kinds together, so that mine will not need my direct work to re-power them: