OS for video communicator? (single purpose device)

[feklee]

I want to set up a PinePhone as a video communicator. It should boot straight into a video chatting application, for example Jitsi Meet:

   

What I do not want:

• Ability to open arbitrary apps:
     
   
  
• Ability to browse the web:
     
     
  
• Ability to select a Jitsi server. (The server is preconfigured.)
  
  

What I may want, but later:

• Ability to see battery status and data consumption.
  
  
• Ability to connect to a WiFi network. Some public networks require authentication on a web page.
     
  For now, it is sufficient if the WiFi networks are preconfigured, and otherwise the phone is connected to the Internet via a mobile network.
  
  
• Ability to receive phone calls, which are merged into the video chat.
  
  
• Ability to make phone calls from the video chat.
   
  
• Ability to connect an external web cam via USB.
  
  

 
What OS would be a good starting point?

What I am considering so far:

• Preferred: Full Linux OS that boots into a locked down web browser which loads the Jitsi Meet URL. I may want to have the option to run a little web server which serves a web page with Jitsi embedded in an iframe.
  
  
• Full Linux OS with the Jitsi Android app running e.g. Shashlik. I have just discovered Shashlik and have not yet tested it.
  
  
• Android based OS with just the Jitsi App. The app opens when the device is turned on. There is no home screen. I’m not sure if that is even possible.