Enhance status messages and layout in HostsManagerApp; improve error handling and testing for status updates

tests/test_main.py

@@ -243,14 +243,17 @@ class TestHostsManagerApp:
             
             app = HostsManagerApp()
             
-            # Mock the query_one method
+            # Mock the query_one method and set_timer to avoid event loop issues
             mock_status = Mock()
             app.query_one = Mock(return_value=mock_status)
+            app.set_timer = Mock()  # Mock the timer to avoid event loop issues
             
             app.update_status("Custom status message")
             
             # Verify status was updated with custom message
             mock_status.update.assert_called_once_with("Custom status message")
+            # Verify timer was set for auto-clearing
+            app.set_timer.assert_called_once()
     
     def test_action_reload(self):
         """Test reload action."""