Set User-Agent on the CLI

Requires writeas-cli v1.1

src/window.vala

@@ -22,6 +22,7 @@ public class WriteAs.MainWindow : Gtk.ApplicationWindow {
     private Gtk.ToggleButton darkmode_button;
 
     private static string data_dir = ".writeas";
+    private static string version = "1.0.0-beta";
 
     private int font_size = 12;
     private bool dark_mode = false;
@@ -264,7 +265,7 @@ public class WriteAs.MainWindow : Gtk.ApplicationWindow {
             text_changed = false;
             }
 
-            var cmd = "sh -c 'cat ~/" + data_dir + "/draft.txt | writeas --font %s'";
+            var cmd = "sh -c 'cat ~/" + data_dir + "/draft.txt | writeas --font %s --user-agent \"writeas-gtk v" + version + "\"'";
             cmd = cmd.printf(fontstyle);
             string stdout, stderr;
             int status;