Steam rate-limits its community member lists by IP (429), so the whole-list download is gone.
Each player is checked as they join with ISteamUser/GetUserGroupList: a member's 'group' row is
added or refreshed, a non-member's deleted, and when Steam won't say (private profile, bad key,
outage) the database stands. A player is asked about at most once per
min_forced_refresh_seconds; css_verify rechecks its targets, offline SteamIDs too. Changing the
group clears the old group's rows. refresh_minutes is gone.
The Web API key goes in configs/plugins/GroupVerify/GroupVerify.json (SteamWebApiKey); every
other setting stays in the database.
New clan_tag setting and css_gv_clantag <tag|-> (@css/root): the scoreboard tag for verified
players without a rank, applied by CS2-Tags. The API gains ClanTag and OnClanTagChanged, so
shared/GroupVerifyApi changes: needs a server restart.