You can use any technology you want that runs on ARM Linux for the Pinephone.
But the hardware is very slow compared to pretty much any other modern phone, you will struggle to get decent performance from web technology.
But the hardware is very slow compared to pretty much any other modern phone, you will struggle to get decent performance from web technology.
Of course you can run UIs for Zig programs in Sciter, just like you can do it for C or C++ programs...