Task #250 — AB CIP + AB Legacy test-client CLIs

Second + third of the four driver test clients. Both follow the same shape as
otopcua-modbus-cli (#249) and consume Driver.Cli.Common for DriverCommandBase +
SnapshotFormatter.

New projects:
  - src/ZB.MOM.WW.OtOpcUa.Driver.AbCip.Cli/ — otopcua-abcip-cli.
    AbCipCommandBase carries gateway (ab://host[:port]/cip-path) + family
    (ControlLogix/CompactLogix/Micro800/GuardLogix) + timeout.
    Commands: probe, read, write, subscribe.
    Value parser covers every AbCipDataType atomic type (Bool, SInt..LInt,
    USInt..ULInt, Real, LReal, String, Dt); Structure writes refused as
    out-of-scope for the CLI.
  - src/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Cli/ — otopcua-ablegacy-cli.
    AbLegacyCommandBase carries gateway + plc-type (Slc500/MicroLogix/Plc5/
    LogixPccc) + timeout.
    Commands: probe (default address N7:0), read, write, subscribe.
    Value parser covers Bit, Int, Long, Float, AnalogInt, String, and the
    three sub-element types (TimerElement / CounterElement / ControlElement
    all land on int32 at the wire).

Tests (35 new, 73 cumulative across the driver CLI family):
  - AB CIP: 17 tests — ParseValue happy-paths for every Logix atomic type,
    failure cases (non-numeric / bool garbage), tag-name synthesis.
  - AB Legacy: 18 tests — ParseValue coverage (Bit / Int / AnalogInt / Long /
    Float / String / sub-elements), PCCC address round-trip in tag names
    including bit-within-word + sub-element syntax.

Docs:
  - docs/Driver.AbCip.Cli.md — family ↔ CIP-path cheat sheet + examples per
    command + typical workflows.
  - docs/Driver.AbLegacy.Cli.md — PCCC address primer (file letters → CLI
    --type) + known ab_server upstream gap cross-ref to #224 close-out.

Wiring:
  - ZB.MOM.WW.OtOpcUa.slnx grew 4 entries (2 src + 2 tests).

Full-solution build clean. `otopcua-abcip-cli --help` + `otopcua-ablegacy-cli
--help` verified end-to-end.

Next up (#251): S7 + TwinCAT CLIs, same pattern.

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

src/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Cli/Commands/WriteCommand.cs

@@ -0,0 +1,81 @@
+using System.Globalization;
+using CliFx.Attributes;
+using CliFx.Infrastructure;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Driver.Cli.Common;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Cli.Commands;
+
+/// <summary>
+///     Write one value to a PCCC file address. Writes to timer / counter / control
+///     sub-elements go through at the wire level but land on the integer field of the
+///     sub-element — the PLC's runtime semantics (edge-triggered EN/DN bits, preset reloads)
+///     are PLC-managed, not CLI-manipulable; write these with caution.
+/// </summary>
+[Command("write", Description = "Write a single PCCC file address.")]
+public sealed class WriteCommand : AbLegacyCommandBase
+{
+    [CommandOption("address", 'a', Description =
+        "PCCC file address — same format as `read`.", IsRequired = true)]
+    public string Address { get; init; } = default!;
+
+    [CommandOption("type", 't', Description =
+        "Bit / Int / Long / Float / AnalogInt / String / TimerElement / CounterElement / " +
+        "ControlElement (default Int).")]
+    public AbLegacyDataType DataType { get; init; } = AbLegacyDataType.Int;
+
+    [CommandOption("value", 'v', Description =
+        "Value to write. Parsed per --type (booleans accept true/false/1/0).",
+        IsRequired = true)]
+    public string Value { get; init; } = default!;
+
+    public override async ValueTask ExecuteAsync(IConsole console)
+    {
+        ConfigureLogging();
+        var ct = console.RegisterCancellationHandler();
+
+        var tagName = ReadCommand.SynthesiseTagName(Address, DataType);
+        var tag = new AbLegacyTagDefinition(
+            Name: tagName,
+            DeviceHostAddress: Gateway,
+            Address: Address,
+            DataType: DataType,
+            Writable: true);
+        var options = BuildOptions([tag]);
+
+        var parsed = ParseValue(Value, DataType);
+
+        await using var driver = new AbLegacyDriver(options, DriverInstanceId);
+        try
+        {
+            await driver.InitializeAsync("{}", ct);
+            var results = await driver.WriteAsync([new WriteRequest(tagName, parsed)], ct);
+            await console.Output.WriteLineAsync(SnapshotFormatter.FormatWrite(Address, results[0]));
+        }
+        finally
+        {
+            await driver.ShutdownAsync(CancellationToken.None);
+        }
+    }
+
+    /// <summary>Parse <c>--value</c> per <see cref="AbLegacyDataType"/>, invariant culture.</summary>
+    internal static object ParseValue(string raw, AbLegacyDataType type) => type switch
+    {
+        AbLegacyDataType.Bit => ParseBool(raw),
+        AbLegacyDataType.Int or AbLegacyDataType.AnalogInt => short.Parse(raw, CultureInfo.InvariantCulture),
+        AbLegacyDataType.Long => int.Parse(raw, CultureInfo.InvariantCulture),
+        AbLegacyDataType.Float => float.Parse(raw, CultureInfo.InvariantCulture),
+        AbLegacyDataType.String => raw,
+        AbLegacyDataType.TimerElement or AbLegacyDataType.CounterElement
+            or AbLegacyDataType.ControlElement => int.Parse(raw, CultureInfo.InvariantCulture),
+        _ => throw new CliFx.Exceptions.CommandException($"Unsupported DataType '{type}' for write."),
+    };
+
+    private static bool ParseBool(string raw) => raw.Trim().ToLowerInvariant() switch
+    {
+        "1" or "true" or "on" or "yes" => true,
+        "0" or "false" or "off" or "no" => false,
+        _ => throw new CliFx.Exceptions.CommandException(
+            $"Boolean value '{raw}' is not recognised. Use true/false, 1/0, on/off, or yes/no."),
+    };
+}