fix & optimize

- fix downloading page unbond size
- auto dispose isolate

lib/data/model/sftp/download_status.dart

@@ -33,6 +33,9 @@ class SftpDownloadStatus {
     switch (event.runtimeType) {
       case SftpWorkerStatus:
         status = event;
+        if (status == SftpWorkerStatus.finished) {
+          worker.dispose();
+        }
         break;
       case double:
         progress = event;

lib/data/model/sftp/download_worker.dart

@@ -24,6 +24,10 @@ class SftpDownloadWorker {
   final worker = Worker();
   final String? privateKey;
 
+  void dispose() {
+    worker.dispose();
+  }
+
   /// Initiate the worker (new thread) and start listen from messages between
   /// the threads
   Future<void> init() async {

lib/data/res/build_data.dart

@@ -2,9 +2,9 @@
 
 class BuildData {
   static const String name = "ServerBox";
-  static const int build = 127;
+  static const int build = 128;
   static const String engine =
       "Flutter 2.10.5 • channel stable • https://github.com/flutter/flutter.git\nFramework • revision 5464c5bac7 (3 weeks ago) • 2022-04-18 09:55:37 -0700\nEngine • revision 57d3bac3dd\nTools • Dart 2.16.2 • DevTools 2.9.2\n";
-  static const String buildAt = "2022-05-07 22:16:13.513462";
+  static const String buildAt = "2022-05-07 22:36:43.297250";
   static const int modifications = 1;
 }