Carlsagan
Unbelievable post lmao.
GrapheneOS is coming out with an anti-explosive detection system that's rolling out in the next few updates. It will use the phone's internal sensors to detect the presence of certain chemical compounds, and shut itself off to prevent explosions.
(This is sarcastic).
I'll be serious now. The phone itself already has safeguards against overheating, and it will protect itself from fires in its default state.
If you have adversaries intercepting your phone, planting explosives inside of it, and sealing it back up, there's absolutely nothing you can do. GrapheneOS can't do anything either because the phone was physically compromised.