Drop the in-card Local/API tab strip — each is now its own admin card with
a normal h2 heading (Local on top, API below). The API key input is
always visible (no more click-to-reveal toggle), matching how cloud
providers actually work. Local keeps the optional key reveal since
local servers usually don't need one.
Dead code removed: wireModelsTabs IIFE and the adm-epApiKeyBtn toggle wire.