feat: add Reverb realtime messaging

app/Http/Requests/Messaging/ManageConversationParticipantRequest.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Http\Requests\Messaging;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class ManageConversationParticipantRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return $this->user() !== null;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'user_id' => 'required|integer|exists:users,id',
+        ];
+    }
+}