Disable appending to an empty result list

assets/js/app.js

@@ -1250,6 +1250,15 @@ const searchPagination=document.querySelector('#searchPagination');
 let displayedSearchRows=[];
 let searchResultGroups=[];
 const searchResultsByPanel=new Map();
+const syncSearchAddButton=panel=>{
+  if(!panel)return;
+  const addButton=panel.querySelector('[data-search-action="append"]');
+  if(!addButton)return;
+  const hasResults=Boolean(searchResultsByPanel.get(panel.id)?.rows.length);
+  addButton.disabled=!hasResults;
+  addButton.setAttribute('aria-disabled',String(!hasResults));
+  addButton.title=hasResults?'Добавить результаты к текущему списку':'Сначала выполните поиск';
+};
 const getSearchRows=panel=>{
   const registryChecked=[...panel.querySelectorAll('.filter-check')].some(label=>label.textContent.includes('Входящие в Реестр ОПК')&&label.querySelector('input')?.checked);
   const systemformingChecked=[...panel.querySelectorAll('.filter-check')].some(label=>label.textContent.includes('Системообразующие организации')&&label.querySelector('input')?.checked);
@@ -1490,6 +1499,7 @@ const updateSearchResults=(panel,action='replace')=>{
     searchResultGroups=[{action:'replace',filters,rows:[...rows]}];
   }
   searchResultsByPanel.set(panel.id,{rows:displayedSearchRows,groups:searchResultGroups});
+  syncSearchAddButton(panel);
   renderSearchResults();
   resetSearchPanel(panel);
 };
@@ -1517,7 +1527,10 @@ searchResults.addEventListener('click',event=>{
     searchResultGroups.splice(groupIndex,1);
     displayedSearchRows=searchResultGroups.flatMap(item=>item.rows);
     const activePanel=document.querySelector('.filter-panel:not([hidden])');
-    if(activePanel)searchResultsByPanel.set(activePanel.id,{rows:displayedSearchRows,groups:searchResultGroups});
+    if(activePanel){
+      searchResultsByPanel.set(activePanel.id,{rows:displayedSearchRows,groups:searchResultGroups});
+      syncSearchAddButton(activePanel);
+    }
     renderSearchResults();
   }
 });
@@ -1544,6 +1557,7 @@ const setFilterPanel=panelName=>{
   const panelState=searchResultsByPanel.get(panelId);
   displayedSearchRows=panelState?.rows||[];
   searchResultGroups=panelState?.groups||[];
+  syncSearchAddButton(document.getElementById(panelId));
   renderSearchResults();
 };
 const createFilterTab=panelName=>{
@@ -1696,6 +1710,7 @@ const initializeFilterSelect=select=>{
   sync();
 };
 const initializeFilterPanel=panel=>{
+  syncSearchAddButton(panel);
   panel.querySelectorAll('select').forEach(initializeFilterSelect);
   panel.querySelectorAll('.search-field').forEach(field=>{
     updateFilterFieldState(field);