feat(appearance): episode images for Next Up & Continue Watching

- Fix black episode thumbnails in the Next Up / Continue Watching rows:
  build the parent Thumb URL from the matched ParentThumbItemId +
  ParentThumbImageTag pair, instead of pairing ParentBackdropItemId with
  the thumb tag (different parent -> 404 -> black). Fixed on mobile
  (ContinueWatchingPoster) and TV (TVPosterCard, TVHeroCarousel).
- Add a "Use episode images for Next Up & Continue Watching" setting
  (default off = series image, matching Jellyfin), wired into the home
  rows on mobile and TV.
- Add helper descriptions under the Appearance settings rows.

components/home/InfiniteScrollingCollectionList.tsx

@@ -15,6 +15,7 @@ import {
 import { SectionHeader } from "@/components/common/SectionHeader";
 import { Text } from "@/components/common/Text";
 import MoviePoster from "@/components/posters/MoviePoster";
+import { useSettings } from "@/utils/atoms/settings";
 import { Colors } from "../../constants/Colors";
 import ContinueWatchingPoster from "../ContinueWatchingPoster";
 import { TouchableItemRouter } from "../common/TouchableItemRouter";
@@ -85,6 +86,7 @@ export const InfiniteScrollingCollectionList: React.FC<Props> = ({
   }, [isSuccess, onLoaded]);
 
   const { t } = useTranslation();
+  const { settings } = useSettings();
 
   // Flatten all pages into a single array (and de-dupe by Id to avoid UI duplicates)
   const allItems = useMemo(() => {
@@ -186,7 +188,10 @@ export const InfiniteScrollingCollectionList: React.FC<Props> = ({
                 `}
               >
                 {item.Type === "Episode" && orientation === "horizontal" && (
-                  <ContinueWatchingPoster item={item} />
+                  <ContinueWatchingPoster
+                    item={item}
+                    useEpisodePoster={settings?.useEpisodeImagesForNextUp}
+                  />
                 )}
                 {item.Type === "Episode" && orientation === "vertical" && (
                   <SeriesPoster item={item} />

components/home/InfiniteScrollingCollectionList.tv.tsx

@@ -24,6 +24,7 @@ import { useScaledTVTypography } from "@/constants/TVTypography";
 import useRouter from "@/hooks/useAppRouter";
 import { useTVItemActionModal } from "@/hooks/useTVItemActionModal";
 import { SortByOption, SortOrderOption } from "@/utils/atoms/filters";
+import { useSettings } from "@/utils/atoms/settings";
 import { scaleSize } from "@/utils/scaleSize";
 
 // Extra padding to accommodate scale animation (1.05x) and glow shadow
@@ -165,6 +166,7 @@ export const InfiniteScrollingCollectionList: React.FC<Props> = ({
     });
 
   const { t } = useTranslation();
+  const { settings } = useSettings();
 
   const allItems = useMemo(() => {
     const items = data?.pages.flat() ?? [];
@@ -225,6 +227,7 @@ export const InfiniteScrollingCollectionList: React.FC<Props> = ({
             hasTVPreferredFocus={isFirstItem}
             onFocus={() => handleItemFocus(item)}
             width={itemWidth}
+            preferEpisodeImage={settings?.useEpisodeImagesForNextUp}
           />
         </View>
       );
@@ -237,6 +240,7 @@ export const InfiniteScrollingCollectionList: React.FC<Props> = ({
       showItemActions,
       handleItemFocus,
       ITEM_GAP,
+      settings?.useEpisodeImagesForNextUp,
     ],
   );
 

components/home/ScrollingCollectionList.tsx

@@ -9,6 +9,7 @@ import { ScrollView, View, type ViewProps } from "react-native";
 import { Text } from "@/components/common/Text";
 import MoviePoster from "@/components/posters/MoviePoster";
 import { useInView } from "@/hooks/useInView";
+import { useSettings } from "@/utils/atoms/settings";
 import ContinueWatchingPoster from "../ContinueWatchingPoster";
 import { TouchableItemRouter } from "../common/TouchableItemRouter";
 import { ItemCardText } from "../ItemCardText";
@@ -50,6 +51,7 @@ export const ScrollingCollectionList: React.FC<Props> = ({
   });
 
   const { t } = useTranslation();
+  const { settings } = useSettings();
 
   // Show skeleton if loading OR if lazy loading is enabled and not in view yet
   const shouldShowSkeleton = isLoading || (enableLazyLoading && !isInView);
@@ -108,7 +110,10 @@ export const ScrollingCollectionList: React.FC<Props> = ({
                 `}
               >
                 {item.Type === "Episode" && orientation === "horizontal" && (
-                  <ContinueWatchingPoster item={item} />
+                  <ContinueWatchingPoster
+                    item={item}
+                    useEpisodePoster={settings?.useEpisodeImagesForNextUp}
+                  />
                 )}
                 {item.Type === "Episode" && orientation === "vertical" && (
                   <SeriesPoster item={item} />

components/home/TVHeroCarousel.tsx

@@ -65,10 +65,11 @@ const HeroCard: React.FC<HeroCardProps> = React.memo(
     const posterUrl = useMemo(() => {
       if (!api) return null;
 
-      // For episodes, always use series thumb
+      // For episodes, always use series thumb.
+      // Matched pair: ParentThumbItemId owns the Thumb tag, not ParentBackdropItemId.
       if (item.Type === "Episode") {
-        if (item.ParentThumbImageTag) {
-          return `${api.basePath}/Items/${item.ParentBackdropItemId}/Images/Thumb?fillHeight=400&quality=80&tag=${item.ParentThumbImageTag}`;
+        if (item.ParentThumbItemId && item.ParentThumbImageTag) {
+          return `${api.basePath}/Items/${item.ParentThumbItemId}/Images/Thumb?fillHeight=400&quality=80&tag=${item.ParentThumbImageTag}`;
         }
         if (item.SeriesId) {
           return `${api.basePath}/Items/${item.SeriesId}/Images/Thumb?fillHeight=400&quality=80`;