feat(stats): separate YouTube channels in the Library (#253)

stats/src/components/anime/AnimeMergeFlow.test.tsx

@@ -45,6 +45,7 @@ function installDom(): () => void {
 
 function libraryItem(animeId: number, title: string, episodeCount: number): AnimeLibraryItem {
   return {
+    mediaKind: 'anime',
     animeId,
     canonicalTitle: title,
     anilistId: null,
@@ -68,7 +69,9 @@ function findButton(container: Element, label: string): HTMLElement {
 
 /** Library cards only expose aria-pressed while selection mode is on. */
 function cardButtons(container: Element): HTMLButtonElement[] {
-  return [...container.querySelectorAll('button[aria-pressed]')] as unknown as HTMLButtonElement[];
+  return [
+    ...container.querySelectorAll('.grid button[aria-pressed]'),
+  ] as unknown as HTMLButtonElement[];
 }
 
 function mergeButton(container: Element): HTMLButtonElement {