Fire embed:standardSite:view from feed viewability, not embed mount (#10736)

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

src/components/Post/Embed/StandardSiteEmbed/index.tsx

@@ -5,7 +5,6 @@ import {plural} from '@lingui/core/macro'
 import {useLingui} from '@lingui/react/macro'
 
 import {useHaptics} from '#/lib/haptics'
-import {useCallOnce} from '#/lib/once'
 import {shareUrl} from '#/lib/sharing'
 import {niceDate} from '#/lib/strings/time'
 import {toNiceDomain} from '#/lib/strings/url-helpers'
@@ -104,12 +103,6 @@ export const StandardSiteEmbed = ({
     }
   }
 
-  useCallOnce(() => {
-    if (!preview) {
-      ax.metric('embed:standardSite:view', {url: view.uri})
-    }
-  })()
-
   if (isStandardPublication) {
     return (
       <PublicationCard

src/view/com/posts/PostFeed.tsx

@@ -12,6 +12,7 @@ import {
 } from 'react-native'
 import {
   type AppBskyActorDefs,
+  AppBskyEmbedExternal,
   AppBskyEmbedVideo,
   type AppBskyFeedDefs,
 } from '@atproto/api'
@@ -58,6 +59,7 @@ import {
 } from '#/components/feeds/PostFeedVideoGridRow'
 import {TrendingInterstitial} from '#/components/interstitials/Trending'
 import {TrendingVideos as TrendingVideosInterstitial} from '#/components/interstitials/TrendingVideos'
+import {isStandardSiteEmbed} from '#/components/Post/Embed/StandardSiteEmbed/utils'
 import {useAnalytics} from '#/analytics'
 import {IS_IOS, IS_NATIVE, IS_WEB} from '#/env'
 import {DiscoverFeedLiveEventFeedsAndTrendingBanner} from '#/features/liveEvents/components/DiscoverFeedLiveEventFeedsAndTrendingBanner'
@@ -905,6 +907,7 @@ let PostFeed = ({
 
   const seenActorWithStatusRef = useRef<Set<string>>(new Set())
   const seenPostUrisRef = useRef<Set<string>>(new Set())
+  const seenStandardSiteUrisRef = useRef<Set<string>>(new Set())
 
   // Helper to calculate position in feed (count only root posts, not interstitials or thread replies)
   const getPostPosition = useNonReactiveCallback(
@@ -974,6 +977,16 @@ let PostFeed = ({
             })
           }
         }
+
+        // Standard site embed view tracking
+        if (
+          AppBskyEmbedExternal.isView(post.embed) &&
+          isStandardSiteEmbed(post.embed.external) &&
+          !seenStandardSiteUrisRef.current.has(post.embed.external.uri)
+        ) {
+          seenStandardSiteUrisRef.current.add(post.embed.external.uri)
+          ax.metric('embed:standardSite:view', {url: post.embed.external.uri})
+        }
       } else if (item.type === 'videoGridRow') {
         // Track each video in the grid row
         for (let i = 0; i < item.items.length; i++) {