fix(driver-modbus-cli): resolve Medium code-review finding (Driver.Modbus.Cli-001)

Add --bit-index, --string-length, and --string-byte-order options to
SubscribeCommand, mirroring ReadCommand, and pass them into ModbusTagDefinition
so that BitInRegister and String type subscriptions use the correct bit index and
string length rather than silently defaulting to bit-0 / zero-length.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli/Commands/SubscribeCommand.cs

@@ -35,6 +35,21 @@ public sealed class SubscribeCommand : ModbusCommandBase
         "BigEndian (default) or WordSwap.")]
     public ModbusByteOrder ByteOrder { get; init; } = ModbusByteOrder.BigEndian;
 
+    // Driver.Modbus.Cli-001: subscribe previously lacked these three options that read and
+    // write both expose. Without them, BitInRegister always watches bit 0 and String runs with
+    // StringLength=0, silently producing wrong results for any subscriber using those types.
+    [CommandOption("bit-index", Description =
+        "For type=BitInRegister: which bit of the holding register (0-15, LSB-first).")]
+    public byte BitIndex { get; init; }
+
+    [CommandOption("string-length", Description =
+        "For type=String: character count (2 per register, rounded up).")]
+    public ushort StringLength { get; init; }
+
+    [CommandOption("string-byte-order", Description =
+        "For type=String: HighByteFirst (standard) or LowByteFirst (DirectLOGIC).")]
+    public ModbusStringByteOrder StringByteOrder { get; init; } = ModbusStringByteOrder.HighByteFirst;
+
     public override async ValueTask ExecuteAsync(IConsole console)
     {
         ConfigureLogging();
@@ -47,7 +62,10 @@ public sealed class SubscribeCommand : ModbusCommandBase
             Address: Address,
             DataType: DataType,
             Writable: false,
-            ByteOrder: ByteOrder);
+            ByteOrder: ByteOrder,
+            BitIndex: BitIndex,
+            StringLength: StringLength,
+            StringByteOrder: StringByteOrder);
         var options = BuildOptions([tag]);
 
         await using var driver = new ModbusDriver(options, DriverInstanceId);