Fix "is read" detection in single/double page mode

In case the last page of a manga was immediately visible or the became visible after the "image spread state" change, the chapter never got marked as read

src/modules/reader/components/viewer/ReaderViewer.tsx

@@ -138,6 +138,7 @@ export const ReaderViewer = forwardRef((_, ref: ForwardedRef<HTMLDivElement | nu
 
         const convertPagesToDoublePageMode = readingMode.value === ReadingMode.DOUBLE_PAGE;
         if (convertPagesToDoublePageMode) {
+            updateCurrentPageIndex(getNextIndexFromPage(getPage(currentPageIndex, actualPages)));
             setPages(actualPages);
             setWasDoublePageMode(readingMode.value === ReadingMode.DOUBLE_PAGE);
         }

src/modules/reader/services/ReaderControls.ts

@@ -375,11 +375,6 @@ export class ReaderControls {
                     return;
                 }
 
-                const hasPageIndexChanged = endReached || pageIndex !== currentPageIndex;
-                if (!hasPageIndexChanged) {
-                    return;
-                }
-
                 ReaderService.downloadAhead(currentChapter, nextChapter, nextChapters, pageIndex, downloadAheadLimit);
 
                 const handleCurrentPageIndexChange = () => {