feat: add OAuth-only self-registration setting

app/Livewire/Settings/OauthRegistration.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Livewire\Settings;
+
+use Livewire\Component;
+
+class OauthRegistration extends Component
+{
+    public bool $is_oauth_registration_enabled = false;
+
+    public function mount()
+    {
+        $settings = instanceSettings();
+        $this->is_oauth_registration_enabled = (bool) $settings->is_oauth_registration_enabled;
+    }
+
+    public function save()
+    {
+        $settings = instanceSettings();
+        $settings->is_oauth_registration_enabled = $this->is_oauth_registration_enabled;
+        $settings->save();
+
+        $this->dispatch('success', 'OAuth registration setting saved.');
+    }
+
+    public function render()
+    {
+        return view('livewire.settings.oauth-registration');
+    }
+}