Roles via Nextcloud groups: sms-admin/manager/viewer + fix OAuth instance_uri

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Traits/EnforcesRoles.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Traits;
+
+use Illuminate\Database\Eloquent\Model;
+
+trait EnforcesRoles
+{
+    private static function canWrite(): bool
+    {
+        return auth()->user()?->hasAnyRole(['sms-admin', 'sms-manager']) ?? false;
+    }
+
+    public static function canCreate(): bool
+    {
+        return static::canWrite();
+    }
+
+    public static function canEdit(Model $record): bool
+    {
+        return static::canWrite();
+    }
+
+    public static function canDelete(Model $record): bool
+    {
+        return static::canWrite();
+    }
+
+    public static function canDeleteAny(): bool
+    {
+        return static::canWrite();
+    }
+}