fix(PawRing): center main pad ring at cy=50 so avatar sits inside it

mainCy=58 shifted the ring below the flex-centered avatar, causing the
image to appear above/half-inside the ring. Setting cy=50 aligns the
ring with the container center; toe beans (cy≈1-10) overflow upward via
SVG overflow:visible, which is the correct paw-print anatomy.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/stories/PawRing.tsx

@@ -35,7 +35,7 @@ export function PawRing({ petId, children, size = 32, onPress }: PawRingProps) {
   // Main pad: slightly larger than the avatar circle, centered horizontally,
   // shifted down so the toe beans have room above.
   const mainCx = 50;
-  const mainCy = 58;
+  const mainCy = 50;
   const mainR = 44;
   const strokeW = Math.max(4, (size / 8)); // thicker ring for larger avatars