Default to Catalog tab when library is empty on first launch

src/window.rs

@@ -1009,8 +1009,11 @@ impl DriftwoodWindow {
                 library_view.populate(records);
             }
             _ => {
-                // Empty database - show empty state
+                // Empty database - show empty state and default to Catalog tab
                 library_view.set_state(LibraryState::Empty);
+                if let Some(view_stack) = self.imp().view_stack.get() {
+                    view_stack.set_visible_child_name("catalog");
+                }
             }
         }