opt: reset file confirm & clean code

flutter/lib/common.dart

@@ -37,8 +37,8 @@ class MyTheme {
 }
 
 final ButtonStyle flatButtonStyle = TextButton.styleFrom(
-  minimumSize: Size(88, 36),
-  padding: EdgeInsets.symmetric(horizontal: 16.0),
+  minimumSize: Size(0, 36),
+  padding: EdgeInsets.symmetric(horizontal: 16.0, vertical: 10.0),
   shape: const RoundedRectangleBorder(
     borderRadius: BorderRadius.all(Radius.circular(2.0)),
   ),

flutter/lib/models/file_model.dart

@@ -418,6 +418,7 @@ class FileModel extends ChangeNotifier {
 
   Future<bool?> showFileConfirmDialog(
       String title, String content, bool showCheckbox) async {
+    fileConfirmCheckboxRemember = false;
     return await DialogManager.show<bool?>(
         (setState, Function(bool? v) close) => CustomAlertDialog(
                 title: Row(
@@ -431,7 +432,9 @@ class FileModel extends ChangeNotifier {
                     crossAxisAlignment: CrossAxisAlignment.start,
                     mainAxisSize: MainAxisSize.min,
                     children: [
-                  Text(translate("This file exists, skip or overwrite this file?"),
+                      Text(
+                          translate(
+                              "This file exists, skip or overwrite this file?"),
                           style: TextStyle(fontWeight: FontWeight.bold)),
                       SizedBox(height: 5),
                       Text(content),