Add a proton init function

lib/proton.dart

@@ -1,3 +1,6 @@
+import 'dart:io';
+
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:servermanager/settings.dart';
 
@@ -20,6 +23,36 @@ class ProtonState extends State<Proton> {
         title: Text("Proton Manager"),
         backgroundColor: Color.fromARGB(255, 100, 0, 0),
       ),
+      body: SingleChildScrollView(
+          child: Padding(
+        padding: const EdgeInsets.all(16),
+        child: Column(children: [
+          ListTile(
+            title: Text("Init Prefix"),
+            subtitle: Text("Resets proton prefix"),
+            leading: Icon(CupertinoIcons.folder_fill),
+            onTap: () async {
+              Directory dir = Directory(
+                  settings.game_path + Platform.pathSeparator + "pfx");
+              // Invoke Proton and reset the prefix.
+              if (dir.existsSync()) {
+                await dir.delete(recursive: true);
+
+                await dir.create(recursive: true);
+              } else {
+                await dir.create(recursive: true);
+              }
+              Platform.environment.putIfAbsent(
+                  "STEAM_COMPAT_CLIENT_INSTALL_PATH", () => "~/.steam");
+              Platform.environment
+                  .putIfAbsent("STEAM_COMPAT_DATA_PATH", () => dir.path);
+
+              await Process.run(
+                  "proton", ["run", "this_program_does_not_exist.exe"]);
+            },
+          )
+        ]),
+      )),
     );
   }
 }