Resolve secret:-prefixed Password + UserCertificatePassword through the shared
ISecretResolver, fail-closed on absent, retiring the cleartext-in-DB path. The
driver-registry factory is synchronous (Func<string,string,IDriver>), so resolution
is done lazily in the async session-open (InitializeAsync, before BuildUserIdentity)
rather than at deserialize — mirroring Task 7's Galaxy pattern and matching its
re-resolve-on-reconnect behavior. Both consumers (username Password and the
certificate-password LoadPkcs12 path via BuildCertificateIdentity) see the resolved
connect-scoped options; _options stays raw (secret: refs intact), no long-lived
plaintext field.
Scope corrections vs the plan (verified against v3): the probe is unauthenticated
GetEndpoints-only and never reads either credential, so it is NOT a resolution site
(comment added, no dead code); OpcUaClientDriverOptions was a sealed class, converted
to sealed record for the with-expression (no positional params → identical JSON; no
reference-equality/dict-key/ToString-log usages → no behavior/leak change).
ISecretResolver threaded via factory Register/CreateInstance + DriverFactoryBootstrap
(real resolver from DI); NullSecretResolver null-object backs test/parse paths only,
fail-closed on secret: refs. TDD: 4 helper tests RED→GREEN; 142 OpcUaClient tests pass.
Replace the bare TCP-connect return in OpcUaClientDriverProbe with a real
OPC UA GetEndpoints discovery handshake (mirroring SelectMatchingEndpointAsync
in the driver). TCP preflight still fast-fails closed ports; the handshake
confirms the remote is actually an OPC UA server, so a live-but-rejecting
non-OPC-UA process now reads RED instead of a false-healthy green.
Cheap-and-fast probe: open TCP socket to the configured endpoint,
close immediately. Surfaces SocketError on failure, latency on
success, "timed out" on caller cancel. Sufficient for the AdminUI
Test Connect "can we reach the host?" question. Richer protocol-
level probes (OPC UA session open, FOCAS handshake, gRPC ping)
are a documented follow-up. Each probe registered as
AddSingleton<IDriverProbe, X> in DriverFactoryBootstrap so they
flow through DI into AdminOperationsActor.
Historian.Wonderware returns a clean "TCP probe not applicable"
result because it communicates over a Windows named pipe, not TCP.
Also adds OpcUaClient + Historian.Wonderware.Client project
references to Host.csproj (both were missing from the driver
ItemGroup).
Joseph Doherty