First slice of F26. Bridges F25's working AsbClient into the M0
`mxaccess::Transport` trait that Session uses to discriminate
operations across NMX and ASB transports.
API additions:
* `mxaccess::AsbTransport<T>` — generic over the same
AsyncRead+AsyncWrite+Unpin+Send+Sync+'static bound that AsbClient
takes. Owns an AsbClient and exposes it via `client_mut()` /
`into_client()`.
* `impl Transport for AsbTransport<T>`:
- `capabilities()` — `buffered_subscribe = false`,
`activate_suspend = false`, `operation_complete_frame = false`
per `design/60-roadmap.md` M5 (no NMX-specific extensions on
ASB).
- `kind()` — `TransportKind::Asb`.
Path-dep wiring: `mxaccess` now imports `mxaccess-asb` +
`mxaccess-asb-nettcp` directly.
Compile-time `Send + Sync + 'static` assertion guards the
trait-bound contract.
2 new tests:
* `asb_transport_kind_is_asb`.
* `asb_transport_capabilities_disable_buffered_and_activate_suspend`.
Stubbed for F26 step 2:
* `Session::connect_asb` constructor that owns TCP open +
preamble + DH handshake orchestration.
* Operation routing that maps ASB types (ItemStatus, RuntimeValue)
back to mxaccess types (MxStatus, DataChange, MxValue).
Stubbed for F26 step 3:
* Subscription routing — Session::subscribe on ASB needs F25
subscription operations (CreateSubscription / AddMonitoredItems
/ Publish), which are not yet implemented.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
8a0f92b6bc