Two test/fixture bugs; NO OtOpcUa driver change.
1. Topology: FocasSimFixture reads an env-overridable endpoint
(OTOPCUA_FOCAS_SIM_ENDPOINT, default localhost:8193) and exposes Host/Port,
but WireBackendTests + WireBackendCoverageTests hardcoded
focas://127.0.0.1:8193. Against a remote fixture the skip-gate passed
(remote reachable) but the driver dialed localhost -> KeyNotFound. Added a
DeviceUri property to the fixture; each test now derives DeviceHost from it.
Recovered 8 of 9.
2. Mock timer endianness (surfaced once #1 let the tests reach the mock): the
last failure read 60397977600 for a 3600 s power-on timer (= 0x3C000000 x 60).
The focas-mock's _wire_timer encoded the minute/msec fields big-endian (_u32),
but cnc_rdtimer's timer fields are LITTLE-endian on real hardware — a
documented, live-31i-B-validated quirk that FocasWireClient.ParseTimer decodes
LE (docs/plans/2026-06-25-focas-pdu-v3-30i-b-support.md). The driver was
correct; the mock was wrong. _wire_timer now emits little-endian (_u32_le).
Suite 9F/1P -> 10/10 against the remote fixture at ~/otopcua-focas.
Integration-sweep follow-up #3.
Joseph Doherty
7982043673