Add a lil check to shadow handling

src/state/cache/post-shadow.ts

@@ -91,9 +91,16 @@ function mergeShadow(
     repostCount = Math.max(0, repostCount)
   }
 
-  if (shadow.embed !== undefined && post.embed) {
+  if ('embed' in shadow) {
+    if (
+      (AppBskyEmbedRecord.isView(post.embed) &&
+        AppBskyEmbedRecord.isView(shadow.embed)) ||
+      (AppBskyEmbedRecordWithMedia.isView(post.embed) &&
+        AppBskyEmbedRecordWithMedia.isView(shadow.embed))
+    ) {
       post.embed = shadow.embed
     }
+  }
 
   return castAsShadow({
     ...post,