Remove dummy touchscreen; fix supervisord & defaults

Remove non-portable dummy_touchscreen InputDevice from Xorg config and adjust dummy_mouse entry. Hardcode supervisord environment/user/display to 'neko' and :99.0 for X, PulseAudio, Firefox, Openbox and the Neko server to simplify runtime on bare-metal. Update /etc/neko/neko.yaml to disable session cookies, enable WebRTC icelite, add nat1to1 mapping with ${LOCAL_IP}, set EPR port range 59000-59100, and disable desktop input. Update json/neko.json to clear the default username (null) and clarify the password-only login note. These changes make the packaged runtime compatible without the custom Xorg driver and streamline defaults for deployment.

json/neko.json

@@ -28,12 +28,12 @@
         }
     ],
     "default_credentials": {
-        "username": "admin",
+        "username": null,
         "password": "admin"
     },
     "notes": [
         {
-            "text": "Regular user password is 'neko'. Change both passwords in /etc/neko/neko.yaml after first login.",
+            "text": "Login is password-only: 'admin' for admin, 'neko' for regular user. Change both in /etc/neko/neko.yaml.",
             "type": "warning"
         },
         {