Always save pages/covers in subfolders

Ensures that pages and covers are grouped together.

app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaCoverScreenModel.kt

@@ -102,8 +102,8 @@ class MangaCoverScreenModel(
             imageSaver.save(
                 Image.Cover(
                     bitmap = bitmap,
-                    name = manga.title,
-                    location = if (temp) Location.Cache else Location.Pictures.create(),
+                    name = "cover",
+                    location = if (temp) Location.Cache else Location.Pictures(manga.title),
                 ),
             )
         }

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

@@ -740,17 +740,14 @@ class ReaderViewModel @JvmOverloads constructor(
 
         val filename = generateFilename(manga, page)
 
-        // Pictures directory.
-        val relativePath = if (readerPreferences.folderPerManga().get()) DiskUtil.buildValidFilename(manga.title) else ""
-
-        // Copy file in background.
+        // Copy file in background
         viewModelScope.launchNonCancellable {
             try {
                 val uri = imageSaver.save(
                     image = Image.Page(
                         inputStream = page.stream!!,
                         name = filename,
-                        location = Location.Pictures.create(relativePath),
+                        location = Location.Pictures(DiskUtil.buildValidFilename(manga.title)),
                     ),
                 )
                 withUIContext {

app/src/main/java/eu/kanade/tachiyomi/ui/reader/setting/ReaderPreferences.kt

@@ -54,8 +54,6 @@ class ReaderPreferences(
 
     fun readerHideThreshold() = preferenceStore.getEnum("reader_hide_threshold", ReaderHideThreshold.LOW)
 
-    fun folderPerManga() = preferenceStore.getBoolean("create_folder_per_manga", false)
-
     fun skipRead() = preferenceStore.getBoolean("skip_read", false)
 
     fun skipFiltered() = preferenceStore.getBoolean("skip_filtered", true)