feat: add setting that allows removing books from recent list when read (#2043)

src/activities/reader/EpubReaderActivity.h

@@ -31,6 +31,9 @@ class EpubReaderActivity final : public Activity {
   bool pendingSyncSaveError = false;
   bool skipNextButtonCheck = false;  // Skip button processing for one frame after subactivity exit
   bool automaticPageTurnActive = false;
+  // Tracks whether this book is currently removed from Recent Books by the
+  // removeReadBooksFromRecents feature (set at End-of-Book, cleared if paged back in).
+  bool recentsEntryRemoved = false;
   // Set when the reader is left at end-of-book and SETTINGS.moveFinishedToReadFolder is on.
   // Consumed in onExit() to relocate the finished book into /Read/.
   bool pendingReadFolderMove = false;