fix(users): preserve timezone in last login timestamp

app/Http/Resources/UserResource.php

@@ -35,7 +35,7 @@ public function toArray(Request $request): array
                 ? Storage::temporaryUrl($this->avatar_url, now()->addHours(24))
                 : null,
             'last_login_at' => $this->last_login_at
-                ? Carbon::parse($this->last_login_at)->format('Y-m-d H:i:s')
+                ? Carbon::parse($this->last_login_at)->toIso8601String()
                 : null,
             'created_at'    => Carbon::parse($this->created_at)->format('Y-m-d'),
             'updated_at'    => Carbon::parse($this->updated_at)->format('Y-m-d'),