Offline state for web tabs in pane

Problem

When a web page tab in a pane fails to load due to offline mode, the pane remains empty or shows a broken page. This gives no clear feedback to the user about why the content isn’t visible.

Expected

• Show a clear offline state inside the pane (e.g., an illustration or icon + message: “No internet connection. This page can’t load right now.”).

• Optionally provide a retry button once the connection is restored.