Issue #3517903: fix hero image quality issue

Problem

When uploading an image for the hero banner, the image style hero_banner_desktop was applied. However, this style outputs a relatively small image compared to the original high-resolution file. As a result, on retina screens and large displays, the hero image appears blurry and lacks sharpness.

Solution

To resolve this, a new image style hero_banner_retina_2x was added. This style ensures the output image retains higher resolution and looks crisp on high-density screens.