In-process transport: dispatch HTTP-like requests through an axum [Router] without a TCP socket.

This crate is transport-agnostic — it knows nothing about JNI, C FFI, or WASM. It provides:

1. [dispatch] / [dispatch_typed] — drive a Router with an envelope
2. [register_app] / [dispatch_from_json] — global app factory for any FFI boundary (JNI, C, WASM)

Example (direct)

let json = dispatch(router, &envelope).await;

Example (FFI pattern)

// At init time (e.g. JNI_OnLoad, DllMain, _start)
vespera_inprocess::register_app(|| create_app());

// On each FFI call
let response_json = vespera_inprocess::dispatch_from_json(request_json);