Refactored folder synchronization logic and improved migration handling (#21)

- Updated `MainViewModel` to skip synchronization until folder migration is completed and added metadata syncing when opening books.
- Modified folder migration to detach existing folder books (converting them to standard local files) before starting a fresh scan.
- Added `detachAllFolderBooks` to `RecentFileDao` and `RecentFilesRepository` to facilitate the migration process.
- Updated `MetadataExtractionWorker` to sync local metadata to the folder immediately after extraction.
- Simplified `FolderSyncWorker` by removing legacy migration lookups and streamlining the reconciliation of local and remote metadata.
- Updated `FolderMigrationDialog` UI text to reflect that books are now read directly from folders without duplication.
- Fixed various indentation and formatting issues across several files.

app/src/main/java/com/aryan/reader/data/RecentFileDao.kt

@@ -87,4 +87,7 @@ interface RecentFileDao {
 
     @Query("SELECT * FROM recent_files WHERE sourceFolderUri IS NOT NULL AND coverImagePath IS NULL AND isDeleted = 0")
     suspend fun getFolderBooksWithoutCovers(): List<RecentFileEntity>
+
+    @Query("UPDATE recent_files SET sourceFolderUri = NULL WHERE sourceFolderUri IS NOT NULL")
+    suspend fun detachAllFolderBooks()
 }

app/src/main/java/com/aryan/reader/data/RecentFilesRepository.kt

@@ -172,6 +172,11 @@ class RecentFilesRepository(private val context: Context) {
         return@withContext recentFileDao.getFolderBooksWithoutCovers().map { it.toRecentFileItem() }
     }
 
+    suspend fun detachAllFolderBooks() = withContext(Dispatchers.IO) {
+        recentFileDao.detachAllFolderBooks()
+        Timber.d("Detached all folder books. They are now standard local files.")
+    }
+
     suspend fun updateBookmarks(bookId: String, bookmarksJson: String) = withContext(Dispatchers.IO) {
         val currentTime = System.currentTimeMillis()
         recentFileDao.updateBookmarks(bookId, bookmarksJson, currentTime)