I need a lean system that sits on top of WhatsApp and lets me schedule outgoing messages while still being able to reply to chats in real time. The single must-have feature is a clean scheduling function—pick a date and time, queue the text, and let it go automatically. If the tool can also show pending, sent, or failed status that would be a plus, but the scheduler is the priority. A small web dashboard, a lightweight desktop app, or direct use of the WhatsApp Cloud API are all acceptable as long as the result is stable and easy to operate on my end. Source code, brief setup instructions, and a quick demo video will be the final hand-off so I can verify everything works before sign-off.