Wanted to spy on my dog, ended up spying on TP-Link

Hacking together something usable out of cloud-first piece of hardware you ended up with is respectable, but I would like to bring up another option to go with if you're choosing a new device: buy camera that doesn't require a phone app to initial setup and serves RTSP out of the box.

What cheap camera doesn't require a phone app and serves RTSP out of the box?

Note that I didn't say "cheap". If price difference comes from manufacturer's hope of selling its cloud service, then the time and effort required to set it up is not worth the money.

If I were to solve one-time task of keeping an eye on someone indoors I would go with USB camera (if lighting conditions allows even the laptop's build in), which is going to be cheaper than ones with IP and WiFi support.