fix(drivers): align probe DriverType strings with AdminUI keys

ModbusDriverProbe.DriverType was "Modbus" but the AdminUI's
ModbusDriverPage persists DriverInstance.DriverType = "ModbusTcp".
GalaxyDriverProbe used the runtime DriverTypeName constant
("GalaxyMxGateway") but the AdminUI saves "Galaxy". The probe DI
lookup is case-insensitive but not name-insensitive, so Test
Connect would fail to find a probe for these two drivers.

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

@@ -22,7 +22,7 @@ public sealed class ModbusDriverProbe : IDriverProbe
     };
 
     /// <inheritdoc />
-    public string DriverType => "Modbus";
+    public string DriverType => "ModbusTcp";
 
     /// <inheritdoc />
     public async Task<DriverProbeResult> ProbeAsync(string configJson, TimeSpan timeout, CancellationToken ct)