Video tab — source photos now show, and load faster

On the Video tab, the original photo shown next to each video now displays correctly, and images across the tab load a size that matches how they're shown.

We fixed the Video tab. The original photo shown beside each generated video — in the detail view, the image view and the "Create video" screen — was not appearing for some videos. Now the source photo displays reliably again.

At the same time, images across the Video tab now load a right-sized version instead of the full-resolution original, so the tab opens faster and uses less data. Full-resolution originals are still used where they matter.