scope feed menu dialog width to web

same class as the previous commit, caught in review: width auto +
minWidth 450 behind gtMobile sizes-to-content on the android tablet
canvas instead of filling the sheet.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/screens/CustomFeed/components/CustomFeedHeader.tsx

@@ -401,7 +401,7 @@ export function CustomFeedHeader({
         <Dialog.Handle />
         <Dialog.ScrollableInner
           label={l`Feed menu`}
-          style={[gtMobile ? {width: 'auto', minWidth: 450} : a.w_full]}>
+          style={[a.w_full, gtMobile && web({width: 'auto', minWidth: 450})]}>
           <DialogInner
             info={info}
             likeUri={likeUri}