Foundation for response decoding. Adds:
* `contracts::ItemStatus` — ports `AsbContracts.cs:639-722`. Wire
layout matches `WriteToStream` exactly: Item (ItemIdentity binary)
→ Status (AsbStatus binary, from F24) → ErrorCode (u16) →
ErrorCodeSpecified (u8 bool). Note this is NOT the DataMember
declaration order — the binary serialiser hand-picks Item-first.
* `encode_item_status_array` / `decode_item_status_array` — same
4-byte int32 count + per-element WriteToStream pattern as the
ItemIdentity array codec.
* `operations::collect_asbidata_payloads(tokens, field_name)` — walks
an NBFX token stream and pulls out `<{field}><ASBIData>{Bytes}
</ASBIData></{field}>` payload bytes. Returns Vec<Vec<u8>> because
some response shapes (ReadResponse) carry multiple ASBIData
payloads (Status + Values).
* `decode_register_items_response` / `decode_unregister_items_response`
— parse SOAP body NBFX tokens into typed RegisterItemsResponse /
UnregisterItemsResponse. The optional ItemCapabilities array (XML-
serialised, not binary) is recorded as a presence flag for now;
decoding the individual ItemRegistration records is a follow-up.
* `build_read_request_body(items)` — simplest unary IASBIDataV2
request, just `<ReadRequest xmlns="..."><Items><ASBIData>...
</ASBIData></Items></ReadRequest>`.
* `OperationError` — typed error for response-decode failures
(`MissingField { field }` and codec wraps).
9 new tests: ItemStatus round-trip (default + with id + with status
payload), ItemStatus array round-trip, RegisterItemsResponse
round-trip via synthetic body, ItemCapabilities presence detection,
UnregisterItemsResponse round-trip, multi-payload extraction (ReadResponse-
shape Status + Values), Read body shape correctness, MissingField
error when Status is absent.
Stubbed for next F25 iteration: Write / PublishWriteComplete /
CreateSubscription / AddMonitoredItems / DeleteMonitoredItems /
Publish builders, ReadResponse + WriteResponse decoders (need
WriteValue / RuntimeValue contract codecs), and the AsbClient
network loop.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
c4bf0a0a04