fix(icons): fix Meta icon clipping in model dropdown (#5542)

MetaIcon's viewBox (265x165) was smaller than the true bounding box of
its three path elements (287.56x191, computed from the actual path
geometry), so the bottom-right of the mark was silently clipped by the
SVG viewport. It was also non-square, so the dropdown row's forced
14x14 icon slot letterboxed it asymmetrically instead of filling it
like every other provider icon.

Fixed the viewBox to the exact computed bounding box, padded to a
square and vertically centered (0 -48.28 287.56 287.56) - matches the
sibling icon convention (GeminiIcon, etc.) of a square viewBox filling
the icon slot edge to edge. Verified by rasterizing both the old and
new viewBox at the actual deployed 14px size.

apps/sim/components/icons.tsx

@@ -3696,7 +3696,7 @@ export function MetaIcon(props: SVGProps<SVGSVGElement>) {
     <svg
       {...props}
       height='1em'
-      viewBox='0 0 265 165'
+      viewBox='0 -48.28 287.56 287.56'
       width='1em'
       xmlns='http://www.w3.org/2000/svg'
     >