fix: route favorites cards through /resource so they survive language switch

Favorites are stored regardless of language but the card click was navigating to /browse?post=<id>&single=1 in the current UI language. When the user switched languages (e.g. zh→en) and tapped a zh-only favorite, the /browse stream couldn't find the post in its English view and showed "Couldn't find this post in the current view".

Make Favorites navigate via /resource/<id> instead. PostRedirect already tries the current UI language first, then falls back to the post's source language and shows a toast. Renamed PopularRankRow's seldom-used `singlePostLink` to `linkToResource` to make the intent obvious; Favorites passes the new prop.

src/components/PopularRankList.tsx

@@ -90,7 +90,7 @@ export function PopularRankRow({
   browseSort = "popular",
   showRank = true,
   showDownload = true,
-  singlePostLink = false,
+  linkToResource = false,
   onFavoriteChange,
 }: {
   post: Post;
@@ -99,7 +99,13 @@ export function PopularRankRow({
   browseSort?: string;
   showRank?: boolean;
   showDownload?: boolean;
-  singlePostLink?: boolean;
+  /**
+   * When true, the card and download button route to `/resource/:id` so the
+   * `PostRedirect` page can fall back to the post's source language if the
+   * current UI language has no translation. Otherwise navigate inside the
+   * `/browse` stream which assumes the post exists in the current language.
+   */
+  linkToResource?: boolean;
   onFavoriteChange?: (postId: string, favorited: boolean) => void;
 }) {
   const { t, lang } = useI18n();
@@ -143,10 +149,13 @@ export function PopularRankRow({
       <button
         type="button"
         onClick={() => {
+          if (linkToResource) {
+            navigate(lp(`/resource/${encodeURIComponent(post.id)}`));
+            return;
+          }
           const params = new URLSearchParams();
           if (browseSort) params.set("sort", browseSort);
           params.set("post", post.id);
-          if (singlePostLink) params.set("single", "1");
           navigate(lp(`/browse?${params.toString()}`));
         }}
         aria-label={r.title}