refactor(opcuaclient): remove vestigial TargetNamespaceKind + UnsMappingTable (#648)

Nothing read the mapping table beyond the startup validator; v3 UNS projection is
explicit via UnsTagReference. Legacy keys in stored DriverConfig are ignored (pinned).
Reverts the docker-dev opc-plc seed workaround from fdee129f.

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

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

@@ -241,10 +241,6 @@ public sealed class OpcUaClientDriver : IDriver, ITagDiscovery, IReadable, IWrit
             if (HasConfigBody(driverConfigJson))
                 _options = OpcUaClientDriverFactoryExtensions.ParseOptions(_driverInstanceId, driverConfigJson);
 
-            // Enforce the Equipment-vs-SystemPlatform choice at startup per driver-specs.md
-            // §8 "Namespace Assignment" — a misconfigured remote fails draft validation here,
-            // not as a runtime surprise.
-            ValidateNamespaceKind(_options);
             ValidateTuning(_options);
 
             var appConfig = await BuildApplicationConfigurationAsync(cancellationToken).ConfigureAwait(false);
@@ -643,42 +639,6 @@ public sealed class OpcUaClientDriver : IDriver, ITagDiscovery, IReadable, IWrit
         return effective < TimeSpan.FromMilliseconds(50) ? 50 : (int)effective.TotalMilliseconds;
     }
 
-    /// <summary>
-    ///     Enforce the §8 "Namespace Assignment" rule at startup. An <c>Equipment</c>-kind
-    ///     instance gateways raw equipment data and therefore needs a config-driven UNS
-    ///     mapping table (remote nodes don't conform to UNS); a <c>SystemPlatform</c>-kind
-    ///     instance gateways processed data whose hierarchy is preserved verbatim, so a
-    ///     UNS mapping table is meaningless and rejected. Throwing here surfaces the
-    ///     misconfiguration as a draft-validation failure rather than a runtime surprise.
-    /// </summary>
-    /// <param name="opts">Driver options containing namespace configuration.</param>
-    internal static void ValidateNamespaceKind(OpcUaClientDriverOptions opts)
-    {
-        switch (opts.TargetNamespaceKind)
-        {
-            case OpcUaTargetNamespaceKind.Equipment:
-                if (opts.UnsMappingTable is null || opts.UnsMappingTable.Count == 0)
-                    throw new InvalidOperationException(
-                        "OpcUaClient driver configured with TargetNamespaceKind=Equipment but no " +
-                        "UnsMappingTable: §8 requires a config-driven remote-to-UNS mapping table " +
-                        "because remote nodes do not conform to UNS by default. Provide a mapping " +
-                        "table or set TargetNamespaceKind=SystemPlatform if the remote exposes " +
-                        "processed data.");
-                break;
-            case OpcUaTargetNamespaceKind.SystemPlatform:
-                if (opts.UnsMappingTable is { Count: > 0 })
-                    throw new InvalidOperationException(
-                        "OpcUaClient driver configured with TargetNamespaceKind=SystemPlatform but " +
-                        "a UnsMappingTable was supplied: processed data preserves its own hierarchy " +
-                        "and a UNS mapping table is ambiguous here. Clear the mapping table or set " +
-                        "TargetNamespaceKind=Equipment if the remote exposes raw equipment data.");
-                break;
-            default:
-                throw new ArgumentOutOfRangeException(
-                    nameof(opts), opts.TargetNamespaceKind, "Unknown TargetNamespaceKind.");
-        }
-    }
-
     /// <summary>
     ///     Build the user-identity token from the driver options. Split out of
     ///     <see cref="InitializeAsync"/> so the failover sweep reuses one identity across