v1.0.63: live sync progress counters, pause/resume, .gitignore fix

- SyncEngine: accepts onProgress callback — emits uploaded/downloaded/
  deleted/bytes counts atomically as each file completes
- SyncWorker: streams progress to WorkManager data so the UI can poll
  it live; reports per-run counters in the completion notification;
  adds pause/resume support
- HomeViewModel/PairDetailViewModel: subscribe to live WorkManager
  progress and surface it via SyncProgress state
- SyncPairEntity/SyncPairDao/SyncDatabase: persist last-run counters
  (uploaded, downloaded, deleted, bytesTransferred) in the DB with a
  Room migration (v3→v4)
- AppModule: provides WorkManager as an injectable singleton
- .gitignore: add .kotlin/ to exclude compiler session files

Security: no new issues — all logging via Timber (debug-only), DB
queries use Room parameterized API, file sharing via FileProvider.

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

app/src/main/kotlin/com/syncflow/worker/SyncWorker.kt

@@ -47,7 +47,14 @@ class SyncWorker @AssistedInject constructor(
         return try {
             val domainPair = pair.toDomain()
             val provider = providerFactory.create(account)
-            val result = syncEngine.sync(domainPair, provider)
+            val result = syncEngine.sync(domainPair, provider) { up, down, del, bytes ->
+                setProgress(workDataOf(
+                    KEY_PROGRESS_UPLOADED to up,
+                    KEY_PROGRESS_DOWNLOADED to down,
+                    KEY_PROGRESS_DELETED to del,
+                    KEY_PROGRESS_BYTES to bytes,
+                ))
+            }
 
             val lines = buildList {
                 if (result.uploaded > 0)   add("↑${result.uploaded}")
@@ -158,6 +165,10 @@ class SyncWorker @AssistedInject constructor(
         const val KEY_PAIR_ID = "pair_id"
         const val KEY_SILENT = "silent"
         const val KEY_RESULT_SUMMARY = "result_summary"
+        const val KEY_PROGRESS_UPLOADED = "prog_up"
+        const val KEY_PROGRESS_DOWNLOADED = "prog_down"
+        const val KEY_PROGRESS_DELETED = "prog_del"
+        const val KEY_PROGRESS_BYTES = "prog_bytes"
         private const val NOTIFICATION_ID = 1001
         private const val RESULT_ID_OFFSET = 2000
         private const val CHANNEL_PROGRESS = "sync_progress"