They’ll just lie about it and disguise the gun turrets as cranes. They’re not invading anyone any time soon, after oil prices fall to pre-Biden levels.
I suggested the idea of a lease to Russia for Sevastapol to be only used by business and private use. I think it is important to keep Russian war ships away from the Ukraine export ports like Odessa, as well as ready access to countries bordering the Mediterranean. I imagine major oligarchs would be happy to use this port for their huge yachts, and trips to the vacation spots in the Mediterranean. They might even put pressure on Putin to accept such an arrangement.
Regarding disguising ships with cranes, I suspect the overall profile of war ships is quite different from that of shipping and pleasure craft. And they cannot be disguised by a few cranes. As a leased property, the leasor, Ukraine, would have full access to the facilities, and recognized/negotiated inspection rights..