Your first app
The hello template in the SDK zip is the canonical first app. It shows a label and
changes the text when you press it.
Each app ships with a manifest.yaml:
id: hello
name: Hello
version: 0.1.0
type: wasm
entry: hello.wasm
Build with cargo build --target wasm32-wasip2 --release from the app directory. The
output .wasm plus manifest.yaml is what the host loads.
See the source in the koba repo: apps/hello.