feat(modbus-rtu): bind Transport mode on options/DTO/factory (string-enum guard)

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus/ModbusDriverFactoryExtensions.cs

@@ -74,6 +74,8 @@ public static class ModbusDriverFactoryExtensions
                 : ParseEnum<ModbusFamily>(dto.Family, "<driver-level>", driverInstanceId, "Family"),
             MelsecSubFamily = dto.MelsecSubFamily is null ? MelsecFamily.Q_L_iQR
                 : ParseEnum<MelsecFamily>(dto.MelsecSubFamily, "<driver-level>", driverInstanceId, "MelsecSubFamily"),
+            Transport = dto.Transport is null ? ModbusTransportMode.Tcp
+                : ParseEnum<ModbusTransportMode>(dto.Transport, "<driver-level>", driverInstanceId, "Transport"),
             AutoProhibitReprobeInterval = dto.AutoProhibitReprobeMs is { } reprobeMs ? TimeSpan.FromMilliseconds(reprobeMs) : null,
             AutoReconnect = dto.AutoReconnect ?? true,
             // v3: the deploy artifact (Wave C) populates rawTags with the cluster's authored raw Modbus
@@ -159,6 +161,8 @@ public static class ModbusDriverFactoryExtensions
         public string? Family { get; init; }
         /// <summary>Gets or sets the Melsec subfamily.</summary>
         public string? MelsecSubFamily { get; init; }
+        /// <summary>Gets or sets the wire transport mode (Tcp / RtuOverTcp). Null defaults to Tcp.</summary>
+        public string? Transport { get; init; }
         /// <summary>Gets or sets the automatic prohibition reprobei interval in milliseconds.</summary>
         public int? AutoProhibitReprobeMs { get; init; }
         /// <summary>Gets or sets a value indicating whether automatic reconnection is enabled.</summary>