fix(catalog): use season posters for episode cards

web/src/components/ContinueWatchingCard.test.tsx

@@ -11,7 +11,7 @@ vi.mock("@/playback/watchPlaybackContext", () => ({
 }));
 
 describe("ContinueWatchingCard", () => {
-  it("prefers the poster image for episodes (poster_url is the horizontal still)", () => {
+  it("prefers the backdrop image for section episodes (backdrop_url is the horizontal still)", () => {
     const queryClient = new QueryClient();
     const markup = renderToStaticMarkup(
       <QueryClientProvider client={queryClient}>
@@ -34,7 +34,7 @@ describe("ContinueWatchingCard", () => {
               position_seconds: 120,
               duration_seconds: 3600,
               progress_updated_at: "2026-03-07T00:00:00Z",
-              poster_url: "/episode-poster.jpg",
+              poster_url: "/season-poster.jpg",
               poster_thumbhash: "",
               backdrop_url: "/episode-backdrop.jpg",
               backdrop_thumbhash: "",
@@ -45,8 +45,8 @@ describe("ContinueWatchingCard", () => {
       </QueryClientProvider>,
     );
 
-    expect(markup).toContain('src="/episode-poster.jpg"');
-    expect(markup).not.toContain('src="/episode-backdrop.jpg"');
+    expect(markup).toContain('src="/episode-backdrop.jpg"');
+    expect(markup).not.toContain('src="/season-poster.jpg"');
   });
 
   it("prefers the backdrop image for movies (poster_url is a vertical poster)", () => {

web/src/components/ContinueWatchingCard.tsx

@@ -144,19 +144,23 @@ export default function ContinueWatchingCard(props: ContinueWatchingCardProps) {
     ? "w-[140px] shrink-0 sm:w-[160px] lg:w-[185px]"
     : "w-[260px] shrink-0 sm:w-[315px]";
   const imageAspect = isPoster ? "aspect-[2/3]" : "aspect-video";
-  // Episodes store the horizontal still in poster_url (see episode_catalog_source.go);
-  // wide-variant movies/series/seasons need the backdrop for the 16:9 card.
-  // Poster variant always wants the vertical poster.
+  const isSectionEpisode = "sectionItem" in props && props.sectionItem?.type === "episode";
+  // Section episode payloads use poster_url for vertical season/series artwork
+  // and backdrop_url for the episode still used by wide cards.
   const imagePrimary = isPoster
     ? card.posterUrl
-    : card.type === "episode"
-      ? card.posterUrl
-      : card.backdropUrl;
+    : isSectionEpisode
+      ? card.backdropUrl
+      : card.type === "episode"
+        ? card.posterUrl
+        : card.backdropUrl;
   const imageFallback = isPoster
     ? card.backdropUrl
-    : card.type === "episode"
-      ? card.backdropUrl
-      : card.posterUrl;
+    : isSectionEpisode
+      ? card.posterUrl
+      : card.type === "episode"
+        ? card.backdropUrl
+        : card.posterUrl;
   const imageSrc = imagePrimary || imageFallback;
 
   return (