feat: sftp perm setting & path copy (#467)

lib/core/extension/sftpfile.dart

@@ -1,4 +1,5 @@
 import 'package:dartssh2/dartssh2.dart';
+import 'package:server_box/view/widget/unix_perm.dart';
 
 extension SftpFileX on SftpFileMode {
   String get str {
@@ -8,6 +9,26 @@ extension SftpFileX on SftpFileMode {
 
     return '$user$group$other';
   }
+
+  UnixPerm toUnixPerm() {
+    return UnixPerm(
+      user: RWX(
+        r: userRead,
+        w: userWrite,
+        x: userExecute,
+      ),
+      group: RWX(
+        r: groupRead,
+        w: groupWrite,
+        x: groupExecute,
+      ),
+      other: RWX(
+        r: otherRead,
+        w: otherWrite,
+        x: otherExecute,
+      ),
+    );
+  }
 }
 
 String _getRoleMode(bool r, bool w, bool x) {