Nevada's entity search (esos.nv.gov/SilverFlume) is behind Imperva Incapsula bot
protection that blocks headless + the residential proxy IPs, and NV has no public
open-data API/bulk dataset. The old adapter scraped the blocked challenge page and
returned available=False for everything (would tell customers a free name is taken)
and also had a NameError bug (f"${CODE}..."). Now NV detects the Incapsula
challenge and returns available=None ('could not determine') with a note to verify
manually on SilverFlume -- never a false 'taken', so it never wrongly blocks an
order. TX remains fully automated via the open-data API.
