feat: several models for the assistant, each with its own name, kind, address and key; a model menu in the chat when there are several (or always, from Аккаунт › Вид), the choice kept for the user

internal/server/web/static/pages.js

@@ -23,6 +23,20 @@
         }, e => alert('Не скопировалось: ' + e.message));
       });
       if (window.UsersTable) window.UsersTable.mount(root);
+      // ИИ-ассистент: a card per model, added from the blank one and taken
+      // away by its «Удалить» (the last one stays).
+      const list = root.querySelector('.ai-models'), blank = root.querySelector('template.ai-model-new');
+      if (list && blank) {
+        root.querySelector('.ai-model-add').onclick = () => {
+          const card = blank.content.firstElementChild.cloneNode(true);
+          list.appendChild(card);
+          card.querySelector('[name=m_name]').focus();
+        };
+        list.addEventListener('click', ev => {
+          const del = ev.target.closest('.ai-model-del');
+          if (del && list.children.length > 1) del.closest('.ai-model').remove();
+        });
+      }
     }
   });