feat: add favorites state and buttons

src/components/messageStream/MessageBubble.tsx

@@ -8,6 +8,7 @@ import { AlbumBubble } from "./bubbles/AlbumBubble";
 import { VideoBubble } from "./bubbles/VideoBubble";
 import { LinkPreviewCard } from "./LinkPreviewCard";
 import { formatDateTime } from "./utils/formatTime";
+import { FavoriteButton } from "../../favorites/FavoriteButton";
 
 type BubbleComponent = ComponentType<{ post: Post }>;
 
@@ -53,6 +54,11 @@ export function MessageBubble({
           isVisual ? "p-0" : "px-4 py-3"
         }`}
       >
+        <FavoriteButton
+          resourceId={post.id}
+          size="sm"
+          className="absolute right-3 top-3 z-20 shadow-lg shadow-black/30"
+        />
         <Bubble post={post} />
         {post.linkPreview ? (
           <div className={isVisual ? "px-4 pt-3" : "mt-3"}>

src/components/messageStream/MessageStream.tsx

@@ -9,6 +9,7 @@ import { FilterChips } from "./FilterChips";
 import { MessageBubble } from "./MessageBubble";
 import { useGroupedByDay } from "./hooks/useGroupedByDay";
 import { usePostStream } from "./hooks/usePostStream";
+import { useFavorites } from "../../favorites/FavoritesProvider";
 
 export type MessageStreamProps = {
   scope: PostScope;
@@ -30,9 +31,14 @@ export function MessageStream({ scope }: MessageStreamProps) {
 
   const { items, isLoading, error, hasMore, loadMore, reset } =
     usePostStream(params);
+  const { ensureFavoriteIds } = useFavorites();
   const groups = useGroupedByDay(items, lang);
   const retryLabel = lang === "zh-CN" ? "重试" : "Retry";
 
+  useEffect(() => {
+    void ensureFavoriteIds(items.map((item) => item.id)).catch(() => undefined);
+  }, [ensureFavoriteIds, items]);
+
   const sentinelRef = useRef<HTMLDivElement>(null);
   const filterBarRef = useRef<HTMLDivElement>(null);
   const hasMoreRef = useRef(hasMore);