Closes [1957](https://github.com/twentyhq/core-team-issues/issues/1957). `getWidgetCardVariant` now returns `side-panel` for mobile and right drawer instead of returning `record-page`. Added stories to WidgetRenderer.stories.tsx because WidgetRenderer is where getWidgetCardVariant is called and the variant is applied. These stories test the actual behavior (mobile/side panel triggering side-column variant) rather than just visual appearance, following the existing pattern of individual behavior-testing stories in this file.