crmne/zapfast ? reverse-engineered prompt

Build me a fast, native desktop WhatsApp app for Linux, macOS, and Windows.

I want it to feel like a real desktop messenger, not a browser wrapper, with a clean chat list, message view, and a smooth way to link my phone by QR code or phone number. It should let me send and read normal messages, replies, edits, reactions, forwards, photos, files, stickers, GIFs, polls, and voice messages. I also want media to play inside the chat, keyboard shortcuts, text selection, notifications, and support for multiple WhatsApp accounts in one window.

Please add light and dark themes, app locking for privacy, and a way to keep chat history stored locally on the computer so older messages can load as I scroll. If you need to look up current docs for the WhatsApp linking flow or desktop notification behavior, go ahead and check online.