In-process transport: composes a kernel directly in the host process.
This is the simplest "attach to a kernel instance" binding — no network, no
IPC. The kernel, its endpoints, and its cache all live in the calling process.
Other transports (IPC, QUIC) front the same Issuer interface over a wire.
The reusable function endpoints (toUpper, reverseList, wrap, split,
greet, echo, compose) are not defined here — they come from the linked
[ikigai_fn] module crate, mounted via [ikigai_fn::space]. This host adds
only its own endpoints: the demo page shape and urn:host:info.