.NET's Uri parses a zone ([fe80::1%eth0]) but drops it from Host, Authority,
AbsoluteUri and ToString(); only DnsSafeHost/IdnHost carry it. The shared
OpcUaEndpointUrlRewriter rebuilt the URL through UriBuilder, so the zone was
lost and link-local endpoints were unroutable. The SDK dials
new Uri(EndpointUrl).IdnHost (TcpByteTransport -> DnsEndPoint), which keeps
it, so splicing the zone back into the string is enough. Kept verbatim
(%eth0, %4, or RFC 6874 %25eth0) so the session dials exactly what
GetEndpoints reached. Applies to the driver, the AdminUI browser and the
Client CLI/UI (all share the rewriter).
Reuses the #806 rewrite cases plus the Client.Shared-specific edges (verbatim
no-op, case-only host difference, escaped path, loud failure on unusable
URLs). Green against the pre-#812 copy: 343/343.