Decompose architecture into 35 atomic tasks across 10 generations for implementation

tasks/setup/test-infrastructure.md

@@ -0,0 +1,39 @@
+---
+id: setup/test-infrastructure
+name: Set up test infrastructure with tokio test helpers and integration test skeleton
+status: pending
+depends_on:
+  - setup/project-init
+scope: narrow
+risk: trivial
+impact: component
+level: implementation
+---
+
+## Description
+
+Set up test infrastructure so that subsequent tasks can write tests as they implement. Add test helpers for creating in-memory transport streams (mock transport), and skeleton integration test files for each component.
+
+The mock transport is critical — it lets us test SSH client/server flows without actual network I/O, per ADR-001's consequence that "mock transports can produce in-memory streams."
+
+## Acceptance Criteria
+
+- [ ] `crates/wraith-core/tests/` directory with empty integration test skeletons: `transport_tests.rs`, `client_tests.rs`, `server_tests.rs`, `auth_tests.rs`
+- [ ] `crates/wraith-core/src/testutil.rs` module (behind `#[cfg(test)]` or a `testutil` feature) exporting `MockTransport` and `MockStream`
+- [ ] `MockStream` wraps `tokio::io::DuplexStream` implementing `AsyncRead + AsyncWrite + Unpin + Send`
+- [ ] `MockTransport` implements `Transport` trait (once defined) returning `MockStream` via `connect()`
+- [ ] `MockTransportAcceptor` implements `TransportAcceptor` (once defined) returning paired `MockStream` via `accept()`
+- [ ] `cargo test` succeeds (even if no real tests yet)
+
+## References
+
+- docs/architecture/transport.md — Transport trait contract
+- docs/architecture/decisions/001-pluggable-transport.md — "mock transports can produce in-memory streams"
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion