Refactor: Replace Certain SyncPreferences with appStateKey

- Revised several fields to utilize `appStateKey` for enhanced state management.
- Modified notification behavior:
  - Removed frequent 'sync completed' notifications to reduce redundancy.
  - Notifications now trigger only on sync errors, streamlining user alerts.

- Users should refer to the 'last sync timestamp' to verify successful synchronizations.
- The timestamp updates only when syncs complete successfully, providing a reliable success indicator.

Signed-off-by: KaiserBh <kaiserbh@proton.me>

app/src/main/java/eu/kanade/presentation/more/settings/screen/SettingsDataScreen.kt

@@ -492,7 +492,7 @@ private fun getSyncNowPref(): Preference.PreferenceGroup {
 private fun getAutomaticSyncGroup(syncPreferences: SyncPreferences): Preference.PreferenceGroup {
     val context = LocalContext.current
     val syncIntervalPref = syncPreferences.syncInterval()
-    val lastSync by syncPreferences.syncLastSync().collectAsState()
+    val lastSync by syncPreferences.lastSyncTimestamp().collectAsState()
 
     return Preference.PreferenceGroup(
         title = stringResource(R.string.pref_sync_service_category),
@@ -516,7 +516,7 @@ private fun getAutomaticSyncGroup(syncPreferences: SyncPreferences): Preference.
                     true
                 },
             ),
-            Preference.PreferenceItem.InfoPreference(stringResource(R.string.last_synchronization, relativeTimeSpanString(lastSync.toEpochMilli()))),
+            Preference.PreferenceItem.InfoPreference(stringResource(R.string.last_synchronization, relativeTimeSpanString(lastSync))),
         ),
     )
 }

app/src/main/java/eu/kanade/tachiyomi/data/backup/BackupRestorer.kt

@@ -36,6 +36,7 @@ import tachiyomi.domain.history.model.HistoryUpdate
 import tachiyomi.domain.library.service.LibraryPreferences
 import tachiyomi.domain.manga.interactor.FetchInterval
 import tachiyomi.domain.manga.model.Manga
+import tachiyomi.domain.sync.SyncPreferences
 import tachiyomi.domain.track.model.Track
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
@@ -59,6 +60,7 @@ class BackupRestorer(
 
     private val preferenceStore: PreferenceStore = Injekt.get()
     private val libraryPreferences: LibraryPreferences = Injekt.get()
+    private val syncPreferences: SyncPreferences = Injekt.get()
 
     private var now = ZonedDateTime.now()
     private var currentFetchWindow = fetchInterval.getWindow(now)
@@ -88,13 +90,7 @@ class BackupRestorer(
         val logFile = writeErrorLog()
 
         if (sync) {
-            notifier.showRestoreComplete(
-                time,
-                errors.size,
-                logFile.parent,
-                logFile.name,
-                contentTitle = context.getString(R.string.library_sync_complete),
-            )
+            syncPreferences.lastSyncTimestamp().set(Date().time)
         } else {
             notifier.showRestoreComplete(time, errors.size, logFile.parent, logFile.name)
         }

app/src/main/java/eu/kanade/tachiyomi/data/sync/SyncManager.kt

@@ -34,6 +34,7 @@ import java.io.File
 import java.io.FileOutputStream
 import java.io.IOException
 import java.time.Instant
+import java.util.Date
 
 /**
  * A manager to handle synchronization tasks in the app, such as updating
@@ -139,7 +140,8 @@ class SyncManager(
 
             // It's local sync no need to restore data. (just update remote data)
             if (filteredFavorites.isEmpty()) {
-                backupNotify.showRestoreComplete(0, 0, "", "", contentTitle = context.getString(R.string.sync_complete))
+                // update the sync timestamp
+                syncPreferences.lastSyncTimestamp().set(Date().time)
                 return
             }
 
@@ -147,7 +149,6 @@ class SyncManager(
             logcat(LogPriority.DEBUG) { "Got Backup Uri: $backupUri" }
             if (backupUri != null) {
                 BackupRestoreJob.start(context, backupUri, sync = true)
-                syncPreferences.syncLastSync().set(Instant.now())
             } else {
                 logcat(LogPriority.ERROR) { "Failed to write sync data to file" }
             }