[Video] Visibility detection view (#4741)

Co-authored-by: Samuel Newman <10959775+mozzius@users.noreply.github.com>

src/view/com/posts/Feed.tsx

@@ -180,6 +180,7 @@ let Feed = ({
   ListHeaderComponent?: () => JSX.Element
   extraData?: any
   savedFeedConfig?: AppBskyActorDefs.SavedFeed
+  outsideHeaderOffset?: number
 }): React.ReactNode => {
   const theme = useTheme()
   const {track} = useAnalytics()

src/view/com/posts/FeedItem.tsx

@@ -356,7 +356,7 @@ let FeedItemInner = ({
             postAuthor={post.author}
             onOpenEmbed={onOpenEmbed}
           />
-          {__DEV__ && gate('videos') && (
+          {gate('video_debug') && (
             <VideoEmbed source="https://lumi.jazco.dev/watch/did:plc:q6gjnaw2blty4crticxkmujt/Qmc8w93UpTa2adJHg4ZhnDPrBs1EsbzrekzPcqF5SwusuZ/playlist.m3u8" />
           )}
           <PostCtrls