v1.0.54: ARCHIVE delete behavior + storage root upload-only allowance

New delete behavior option: "Archive deleted" — when a file is deleted
from the phone in a TWO_WAY pair, it moves to _Deleted/<path> on remote
instead of being permanently deleted from the backup.

Also allows storage root (/storage/emulated/0) for UPLOAD_ONLY pairs so
whole-phone backup syncs work; only blocks root when sync direction would
write files locally.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/src/main/kotlin/com/syncflow/domain/model/SyncPair.kt

@@ -58,6 +58,7 @@ enum class ConflictStrategy(val label: String) {
 enum class DeleteBehavior(val label: String, val description: String) {
     MIRROR("Mirror deletions", "Delete on target when deleted on source"),
     KEEP("Keep deleted files", "Never delete — only add/update"),
+    ARCHIVE("Archive deleted", "Move files deleted from phone to _Deleted/ folder on remote"),
 }
 
 enum class ScheduleType(val label: String) {

app/src/main/kotlin/com/syncflow/domain/sync/SyncEngine.kt

@@ -34,10 +34,11 @@ class SyncEngine @Inject constructor(
     @ApplicationContext private val context: Context,
 ) {
     suspend fun sync(pair: SyncPair, provider: CloudProvider): SyncResult {
-        if (!pair.localPath.startsWith("content://")) {
+        if (!pair.localPath.startsWith("content://") &&
+            pair.syncDirection != SyncDirection.UPLOAD_ONLY) {
             val canonical = runCatching { File(pair.localPath).canonicalPath }.getOrElse { pair.localPath }
             if (canonical == "/storage/emulated/0") {
-                val msg = "Local folder is the storage root — Android blocks writes here. Edit the pair and select a subfolder."
+                val msg = "Local folder is the storage root — Android blocks writes here. Use Upload Only direction, or select a subfolder."
                 syncPairDao.updateSyncResult(pair.id, Instant.now(), SyncStatus.FAILED, 0)
                 logEvent(pair.id, SyncEventType.SYNC_FAILED, null, msg, 0)
                 return SyncResult(failedFiles = 1, error = Exception(msg))
@@ -166,10 +167,20 @@ class SyncEngine @Inject constructor(
                                 FileOutcome(deleted = 1)
                             }
                             SyncDecision.DELETE_REMOTE -> {
-                                runCatching { provider.deleteFile("${pair.remotePath}/$rel") }
-                                    .onFailure { e -> Timber.e(e, "SyncEngine: DELETE_REMOTE failed for $rel") }
-                                fileStateDao.delete(pair.id, rel)
-                                logEvent(pair.id, SyncEventType.FILE_DELETED, rel, "remote", 0)
+                                if (pair.deleteBehavior == DeleteBehavior.ARCHIVE) {
+                                    val archivePath = "${pair.remotePath}/_Deleted/$rel"
+                                    runCatching {
+                                        ensureRemoteDirs(provider, "${pair.remotePath}/_Deleted", rel)
+                                        provider.moveFile("${pair.remotePath}/$rel", archivePath).getOrThrow()
+                                    }.onFailure { e -> Timber.e(e, "SyncEngine: ARCHIVE failed for $rel") }
+                                    fileStateDao.delete(pair.id, rel)
+                                    logEvent(pair.id, SyncEventType.FILE_DELETED, rel, "archived", 0)
+                                } else {
+                                    runCatching { provider.deleteFile("${pair.remotePath}/$rel") }
+                                        .onFailure { e -> Timber.e(e, "SyncEngine: DELETE_REMOTE failed for $rel") }
+                                    fileStateDao.delete(pair.id, rel)
+                                    logEvent(pair.id, SyncEventType.FILE_DELETED, rel, "remote", 0)
+                                }
                                 FileOutcome(deleted = 1)
                             }
                             SyncDecision.CONFLICT -> {

version.properties

@@ -1,2 +1,2 @@
-VERSION_NAME=1.0.53
-VERSION_CODE=54
+VERSION_NAME=1.0.54
+VERSION_CODE=55