fix: enqueue duplicate chapters for deletion after marking as read

[leodyversemilla07]

Summary

Fixes #2454

Root Cause

In updateChapterProgressOnComplete(), when duplicate chapters are auto-marked as read (via the 'Mark duplicate chapters as read' setting), enqueueChaptersToDelete() was never called for them.

The code used mapNotNull { ChapterUpdate(...) } which immediately converted full Chapter objects into lightweight ChapterUpdate objects (only id + read flag). This discarded the full chapter data required by downloadManager.enqueueChaptersToDelete(), and the delete call was simply missing from this code path.

Change

File: app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderViewModel.kt

Replaced mapNotNull { ChapterUpdate } with filter { Chapter } to retain full Chapter objects, then:

• Mark duplicates read via inline .map { ChapterUpdate(...) } — identical behavior as before
• After marking read, enqueue downloaded duplicates for deletion via downloadManager.enqueueChaptersToDelete(), using the same removeAfterReadSlots != -1 guard that protects the existing deleteChapterIfNeeded() call

// Before
val duplicateUnreadChapters = getUnfilteredChapterList()
    .mapNotNull { chapter ->
        if (!chapter.read && chapter.isRecognizedNumber &&
            chapter.chapterNumber.toFloat() == readerChapter.chapter.chapter_number
        ) {
            ChapterUpdate(id = chapter.id, read = true)
        } else { null }
    }
updateChapter.awaitAll(duplicateUnreadChapters)

// After
val duplicateChapters = getUnfilteredChapterList()
    .filter { chapter ->
        !chapter.read &&
            chapter.isRecognizedNumber &&
            chapter.chapterNumber.toFloat() == readerChapter.chapter.chapter_number
    }
updateChapter.awaitAll(duplicateChapters.map { ChapterUpdate(id = it.id, read = true) })

if (downloadPreferences.removeAfterReadSlots().get() != -1) {
    val manga = manga ?: return
    downloadManager.enqueueChaptersToDelete(duplicateChapters, manga)
}