fix immutability errors

src/view/com/pager/TabBar.tsx

@@ -331,7 +331,7 @@ export function TabBar({
             syncScrollState.set('unsynced')
           }}
           onScroll={e => {
-            scrollX.value = Math.round(e.nativeEvent.contentOffset.x)
+            scrollX.set(Math.round(e.nativeEvent.contentOffset.x))
           }}>
           <Animated.View
             onLayout={e => {

src/view/com/posts/PostFeed.tsx

@@ -226,7 +226,8 @@ let PostFeed = ({
   const initialNumToRender = useInitialNumToRender()
   const feedFeedback = useFeedFeedbackContext()
   const [isPTRing, setIsPTRing] = useState(false)
-  const lastFetchRef = useRef<number>(Date.now())
+  const [firstFetchTime] = useState(() => Date.now())
+  const lastFetchRef = useRef<number>(firstFetchTime)
   const [feedType, feedUriOrActorDid, feedTab] = feed.split('|')
   const {gtMobile} = useBreakpoints()
   const {rightNavVisible} = useLayoutBreakpoints()
@@ -263,9 +264,11 @@ let PostFeed = ({
     fetchNextPage,
   } = usePostFeedQuery(feed, feedParams, opts)
   const lastFetchedAt = data?.pages[0].fetchedAt
-  if (lastFetchedAt) {
-    lastFetchRef.current = lastFetchedAt
-  }
+  useEffect(() => {
+    if (lastFetchedAt) {
+      lastFetchRef.current = lastFetchedAt
+    }
+  }, [lastFetchedAt])
   const isEmpty = useMemo(
     () => !isFetching && !data?.pages?.some(page => page.slices.length),
     [isFetching, data],

src/view/com/util/Views.web.tsx

@@ -103,6 +103,8 @@ export const FlatList_INTERNAL = React.forwardRef(function FlatListImpl<ItemT>(
       paddingTop: Math.abs(contentOffset.y),
     })
   }
+  // @ts-expect-error web only
+  let dataSet = props.dataSet || {}
   if (desktopFixedHeight) {
     if (typeof desktopFixedHeight === 'number') {
       // @ts-expect-error Web only -prf
@@ -121,10 +123,7 @@ export const FlatList_INTERNAL = React.forwardRef(function FlatListImpl<ItemT>(
       // around this, we set data-stable-gutters which can then be
       // styled in our external CSS.
       // -prf
-      // @ts-expect-error web only -prf
-      props.dataSet = props.dataSet || {}
-      // @ts-expect-error web only -prf
-      props.dataSet.stableGutters = '1'
+      dataSet = {...dataSet, stableGutters: '1'}
     }
   }
   return (
@@ -133,6 +132,8 @@ export const FlatList_INTERNAL = React.forwardRef(function FlatListImpl<ItemT>(
       contentContainerStyle={[styles.contentContainer, contentContainerStyle]}
       style={style}
       contentOffset={contentOffset}
+      // @ts-expect-error web only
+      dataSet={dataSet}
       {...props}
     />
   )