Keep the video info carousel aligned across window resizes

The carousel's lazy stack kept the old widths of cards it had laid out
off-screen, so after a resize (tab bar to split view sidebar on iPad,
rotation) every later card sat at a stale offset and the current card
landed beside the viewport. The stack now takes a new identity per
card width, and the existing re-snap aligns the current card.

Swapping between the tab bar and the sidebar also rebuilds the page,
which reset the carousel to the video it was opened on. The page's
position and continuation-loaded videos now live on its queue context,
fresh for every push, so a rebuilt page resumes where it was.

Yattee/Views/Video/VideoInfoView.swift

@@ -348,9 +348,11 @@ struct VideoInfoView: View {
             #if !os(tvOS)
             VideoInfoPlayThumbnailTip.isToolbarLayout = showsThumbnailPlayTip
             #endif
-            // Initialize current index from queue context
+            // Initialize current index from queue context, resuming where this
+            // page was before a layout swap rebuilt it
             if currentVideoIndex == nil, let context = videoQueueContext {
-                currentVideoIndex = context.videoIndex
+                extendedVideoList = context.pageState.extendedVideoList
+                currentVideoIndex = context.pageState.currentVideoIndex ?? context.videoIndex
             }
             
             // Load initial video data (only if video is already loaded)
@@ -387,6 +389,8 @@ struct VideoInfoView: View {
             bookmarkSaveTask?.cancel()
         }
         .onChange(of: currentVideoIndex) { oldValue, newValue in
+            videoQueueContext?.pageState.currentVideoIndex = newValue
+
             // Skip if this is the initial value setting (handled by onAppear)
             guard oldValue != nil else { return }
 
@@ -1004,6 +1008,12 @@ struct VideoInfoView: View {
                     }
                 }
                 .scrollTargetLayout()
+                // The lazy stack keeps the old widths of cards it laid out
+                // off-screen, so after a resize (split view sidebar appearing,
+                // rotation, Duo unfold) every later card sits at a stale offset
+                // and the re-snap below lands between cards. A new identity per
+                // width drops those cached sizes.
+                .id(cardWidth)
             }
             // Pin the viewport to the page width so paging stays aligned even
             // when the scroll view extends under a horizontal safe area (iPhone
@@ -2745,6 +2755,7 @@ struct VideoInfoView: View {
             let videosToAdd = Array(newVideos.prefix(remainingCapacity))
             
             extendedVideoList.append(contentsOf: videosToAdd)
+            videoQueueContext?.pageState.extendedVideoList = extendedVideoList
         } catch {
             loadMoreError = error.localizedDescription
         }