Grav may fit your needs.

let us know when you reach 1.21 gigawatts

I’m not familiar with Amazon blink cameras. I use a reoLink and a Raspberry Pi for two cameras that go to a dedicated Zone Minder NVR server which is firewalled off from any internet access or access to other networks within my house.
reolink was pretty easy, blocking all wan traffic is very important - I’m sure like any store-bought solution. the raspberry pi is low quality and obviosuly a diy solution, but is ok. zoneminder is one of a handful of open source nvr softwares. It’s not great in my opinion. I don’t think it uses resources efficiently and it’s a bit of a pain to set up initially. But from what i read all of these opensource nvr apps have their quirks.

i read good things about amcrest cameras

curious, why aren’t you able to self-host your blink cameras; are they ip cameras and is there an rtp stream you can capture?

I’m interested in seeing what you come up with.

Does something like podHoarder fit the bill?

Second this - i tend to follow the same scheme