banc-host 0.0.4

Host-side fixtures and runner for the banc HIL test framework.

The shape of a banc test suite:

use banc_host::{run, BancTest, TestCx};

fn main() -> std::process::ExitCode {
    run(vec![BancTest::new("blink_observed", |cx| {
        Box::pin(async move {
            let assistant = cx.rig.assistant("a0").await?;
            // drive the target, assert on assistant-observed ground truth
            Ok(())
        })
    })])
}

On a machine without a rig (no banc-rig.toml, no BANC_RIG), every test reports ignored with a reason — never passed, never failed — so cargo test stays green off-rig and honest on-rig.