Crops a photo with the brand's signature circular arc, used on report covers and pillar dividers, with a thin accent rim following the curve.

```jsx
<CurvedPhotoMask src="/assets/photos/staff.jpg" alt="Nashville PBS staff" corner="bottom-left" accent="var(--pbs-blue)" height={320} />
<CurvedPhotoMask src={cover} at="14.7% 111%" radius="73.8%" accent="var(--accent-teal)" rim={5} height="100%" />
```

`corner` anchors the circle at a page corner; `at` places its center exactly (a CSS position inside the box) and is how the approved report cover and pillar divider are reproduced: cover `at="14.7% 111%"` with a radius of 85% of the page width, divider `at="20.6% 112%"` with 78% of the page width (`radius` is a clip-path length, so percentages resolve against the box's diagonal; give it px when the box size is known). `accent` should match the page behind it unless the rim is wanted; `rim={0}` hides it. `position` sets the photo's object-position so faces stay inside the circle.