feat(otopcua): add ITagDiscovery.RediscoverPolicy + per-driver assignments (follow-up B)

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient/OpcUaClientDriver.cs

@@ -826,6 +826,14 @@ public sealed class OpcUaClientDriver : IDriver, ITagDiscovery, IReadable, IWrit
 
     // ---- ITagDiscovery ----
 
+    /// <summary>
+    ///     Run-once: <see cref="DiscoverAsync"/> recursively browses the remote server's address
+    ///     space and registers every variable within the single call (browse + enrich passes are
+    ///     fully awaited) — nothing fills in asynchronously after connect, so a single discovery
+    ///     pass is sufficient.
+    /// </summary>
+    public DiscoveryRediscoverPolicy RediscoverPolicy => DiscoveryRediscoverPolicy.Once;
+
     /// <summary>Discovers the remote OPC UA server's address space and materializes it through the supplied builder.</summary>
     /// <param name="builder">Address space builder for materializing discovered nodes.</param>
     /// <param name="cancellationToken">Cancellation token for the operation.</param>