Adds the public high-level entry point for the ASB transport.
Parallel to the NMX-shaped `Session` (rather than unified) because
NMX's `Session` carries CallbackExporter / callback router task /
recovery broadcast / INmxService2 mutex orchestration that has no
ASB analogue — and ASB's request/response loop over a single TCP
stream maps naturally to `Mutex<AsbClient>` that would be foreign
to NMX. Two paths converge at the consumer-facing API but stay
distinct at the orchestration layer.
Struct shape:
```rust
pub struct AsbSession { inner: Arc<AsbSessionInner> }
struct AsbSessionInner {
transport: Mutex<AsbTransport<TcpStream>>,
connect_response: ConnectResponse,
}
```
`Clone + Send + Sync` — clones share state through `Arc`, lock
serialises operations. Compile-time `assert_clone_send_sync` test
guards the contract.
API:
* `connect(endpoint, passphrase, crypto_parameters, via_uri,
connection_id)` — full bring-up (TCP + preamble + DH handshake).
* `from_transport(transport, connect_response)` — build from an
existing transport (tests, custom transports).
* `connect_response()` — surface the negotiated lifetime /
Apollo flag.
Operation methods forward to AsbClient:
* `register_items` / `unregister_items` / `read` / `write`
* `keep_alive` / `disconnect`
* `create_subscription` / `add_monitored_items` / `publish` /
`delete_monitored_items` / `delete_subscription`
* `publish_write_complete`
ClientError → mxaccess::Error mapping via
`ConnectionError::TransportFailure` (consistent with F26 step 2).
1 new test:
* `asb_session_is_clone_send_sync` — compile-time trait-bound
assertion.
Workspace: 702 tests pass.
Stubbed for next F26 iteration:
* `Stream<Item = MonitoredItemValue>` subscription handle that
internally drives a publish-loop. Today consumers loop
`publish().await` themselves.
* Recovery / reconnect policy — needs a captured ASB-side
disconnect to inform the retry strategy.
* Live-probe wire-byte reconciliation against the WCF DataContract
XML serializer's actual output.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
e3baeb8803