Earlier split into 4 flat cards wasn't what was asked for. Restore to
a single 'Add Models' card with two tabs at the top:
Local → Add form + Added Local Models list
API → Add form + Added API Endpoints list
Probe / Clear-offline live on the card header and act on both lists.
Active tab is remembered in localStorage so the user lands back where
they were. All form/list IDs preserved (adm-epLocalUrl, adm-epList-local,
adm-epList-api, etc.) so admin.js continues to work unchanged.
Replaces the .adm-section-toggle fold-open JS with a tab-switcher; the
fold elements no longer exist so the old handler was already a no-op.
8ef9b8b215