I'm after a watch that I can put on a kid when they are on their own at a park etc.

What I'd like:

• It's own data connection so it doesn't need a phone with it
• Home Assistant support so I can track it remotely via home assistant, automations, etc
• Some way of calling them when it's time to come home, or them calling us when needed
• We don't have an iPhone so I think Apple is out since it needs an iPhone for setup
• No subscriptions outside of the cost of the cellphone plan
• Preferably doesn't need OEM servers, just connect to Home Assistant
• Handling knocks and bumps would be a bonus
• If you can run a non-google OS without tracking etc GrapheneOS style then yay but I don't know if that exists

Any suggestions?