feat: unify sync functionality with event-driven UI updates

- Refactored navbar sync button to dispatch 'sync-completed' event
- Configs page: removed duplicate 'Импорт с сервера' button, added auto-refresh on sync
- Projects page: wrapped initialization in DOMContentLoaded, added auto-refresh on sync
- Pricelists page: added auto-refresh on sync completion
- Consistent UX: all lists update automatically after 'Синхронизация' button click
- Removed code duplication: importConfigsFromServer() function no longer needed
- Event-driven architecture enables easy extension to other pages

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

web/templates/pricelists.html

@@ -235,6 +235,12 @@
     document.addEventListener('DOMContentLoaded', function() {
         checkPricelistWritePermission();
         loadPricelists(1);
+
+        // Listen for sync completion events from navbar
+        window.addEventListener('sync-completed', function(e) {
+            // Reload pricelists on sync completion
+            loadPricelists(1);
+        });
     });
 </script>
 {{end}}