fix: user post feed view

components/social/post/use-post-scroll-feed.ts

@@ -41,6 +41,10 @@ export function usePostScrollFeed(fetchPage: FetchPage) {
   const startedRef = useRef(false);
   const cursorRef = useRef<FeedCursor | null>(null);
   const anchorIdRef = useRef<string | null>(null);
+  // Every post id we've already appended — used to dedupe AND to detect a
+  // stalled cursor (a page that adds nothing new), which we treat as the end
+  // so a backend ordering hiccup can never become an infinite fetch loop.
+  const idsRef = useRef<Set<string>>(new Set());
 
   // Append the next older page, keyed off the last loaded post.
   const loadOlder = useCallback(async () => {
@@ -48,13 +52,15 @@ export function usePostScrollFeed(fetchPage: FetchPage) {
     fetchingRef.current = true;
     try {
       const rows = (await fetchPage(cursorRef.current, PAGE)) ?? [];
-      setFeed((prev) => {
-        const seen = new Set(prev.map((p) => p.id));
-        const merged = [...prev, ...rows.filter((p) => !seen.has(p.id))];
-        if (merged.length > 0) cursorRef.current = cursorOf(merged[merged.length - 1]);
-        return merged;
-      });
-      if (rows.length < PAGE) setHasMore(false);
+      const fresh = rows.filter((p) => !idsRef.current.has(p.id));
+      if (fresh.length > 0) {
+        fresh.forEach((p) => idsRef.current.add(p.id));
+        // rows come back newest→oldest; the oldest fresh row is the next cursor.
+        cursorRef.current = cursorOf(fresh[fresh.length - 1]);
+        setFeed((prev) => [...prev, ...fresh]);
+      }
+      // Stop on a short page OR a page that produced nothing new (stalled).
+      if (rows.length < PAGE || fresh.length === 0) setHasMore(false);
     } catch {
       setHasMore(false);
       setError((e) => e ?? "Could not load posts.");
@@ -80,6 +86,7 @@ export function usePostScrollFeed(fetchPage: FetchPage) {
           if (anchor) {
             anchorIdRef.current = anchor.id;
             cursorRef.current = cursorOf(anchor);
+            idsRef.current.add(anchor.id);
             setFeed([anchor]);
             setLoading(false);
             await loadOlder(); // posts older than the anchor