The AdminUI OPC UA browse picker connected to the EndpointUrl the server
advertised in GetEndpoints verbatim, so behind NAT / a container port
publish it dialled the server's private hostname + internal port and
failed DNS where the runtime driver (which rewrites per #676) connected.
- Move the rewrite to the shared OpcUaEndpointUrlRewriter (.Contracts,
pure Uri logic, no SDK dependency) and the policy+mode selection to
OpcUaEndpointSelection (.Session leaf). Driver and browser both select
through it, so the browse connects exactly where the driver does.
- Policy/mode filter, server certificate and strict browse PKI
(no auto-accept) are unchanged.
- Unit tests: rewrite (host/port differ, same, IPv6 both sides, path
kept, port-less, scheme mismatch untouched), browser selection seam.
- Live NAT tests (Fixture=opc-plc-nat, OPCUA_NAT_ENDPOINT): browse via a
published port with a premise check that the advertised host:port
differs and does not resolve, nsu= round-trip, unreachable endpoint
fails cleanly, SignAndEncrypt reaches the server and is refused
BadCertificateUntrusted. Verified red without the rewrite.
Refs #806