//! Master-side smoke tests, no real gRPC transport, just the
//! `Master` struct's task-dispatch contract.
//!
//! Per GOSSAN_DEPTH_CONTRACT A21:
//! - With zero workers, `dispatch_task` returns `Err("No workers connected")`.
//! - `Master::new()` produces a workers-empty / tasks-empty state.
//!
//! End-to-end gRPC + 2 workers + result-merge tests live in
//! `tests/cluster_e2e.rs` (open work, needs a tonic transport
//! harness to exercise the worker-registration handshake).
use Master;
async