example: mesh using api from rust

[michaelneale]

This just shows how we can consume mesh as a "SDK"/api in process.

Pulls it in off a commit for now as a dependency.

Uses: Mesh-LLM/mesh-llm#736

something like:

use mesh_llm_host_runtime::sdk::{EmbeddedMeshNodeConfig, start_embedded_node};

let config = EmbeddedMeshNodeConfig::builder()
    .client()
    .auto_join(true)
    .api_port(9337)
    .console_port(3131)
    .console_ui(false)
    .build();

let node = start_embedded_node(config).await?;
let api_base = node.api_base_url();
let status = node.status().await?;

node.stop().await?;