fix(driver-modbus-cli): resolve Low code-review findings (Driver.Modbus.Cli-003,004,005,006,007,008)

- Driver.Modbus.Cli-003: ModbusCommandBase.ValidateEndpoint rejects
  --port outside 1..65535, non-positive --timeout-ms, and --unit-id
  outside 1..247.
- Driver.Modbus.Cli-004: wrapped SubscribeCommand's OnDataChange handler
  body in a try/catch (warn-and-swallow) and serialised the console
  write through a lock.
- Driver.Modbus.Cli-005: Probe / Read / Write now catch the
  cancellation-during-init OperationCanceledException and print
  'Cancelled.' instead of dumping a stack trace.
- Driver.Modbus.Cli-006: ProbeCommand.ComputeVerdict derives the headline
  from BOTH the driver state and the probe snapshot's OPC UA quality
  class so the headline can't disagree with the wire result.
- Driver.Modbus.Cli-007: docs/Driver.Modbus.Cli.md carries an explicit
  'CLI scope' callout — the address-string grammar is a DriverConfig
  JSON feature; the CLI takes the structured triple only.
- Driver.Modbus.Cli-008: pinned BuildOptions, ValidateEndpoint, the
  region-validation guards, ComputeVerdict, and the cancellation-during-
  initialize paths.

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

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

@@ -1,5 +1,6 @@
 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.Modbus.Cli.Commands;
@@ -21,6 +22,7 @@ public sealed class ProbeCommand : ModbusCommandBase
     public override async ValueTask ExecuteAsync(IConsole console)
     {
         ConfigureLogging();
+        ValidateEndpoint();
         var ct = console.RegisterCancellationHandler();
 
         // Build with one probe tag + Probe.Enabled=false so InitializeAsync connects the
@@ -39,17 +41,59 @@ public sealed class ProbeCommand : ModbusCommandBase
             var snapshot = await driver.ReadAsync(["__probe"], ct);
             var health = driver.GetHealth();
 
+            // Driver.Modbus.Cli-006: derive the headline verdict from BOTH the driver state
+            // AND the probe-read StatusCode so the operator never sees the previous
+            // contradictory pair (`Health: Healthy` over a Bad snapshot line). The bare
+            // driver state is still printed below for diagnostics, but the verdict is what
+            // the operator scans first.
+            var verdict = ComputeVerdict(health.State, snapshot[0].StatusCode);
+
             await console.Output.WriteLineAsync($"Host:         {Host}:{Port} (unit {UnitId})");
-            await console.Output.WriteLineAsync($"Health:       {health.State}");
+            await console.Output.WriteLineAsync($"Verdict:      {verdict}");
+            await console.Output.WriteLineAsync($"Driver state: {health.State}");
             if (health.LastError is { } err)
                 await console.Output.WriteLineAsync($"Last error:   {err}");
             await console.Output.WriteLineAsync();
             await console.Output.WriteLineAsync(
                 SnapshotFormatter.Format($"HR[{ProbeAddress}]", snapshot[0]));
         }
+        catch (OperationCanceledException) when (ct.IsCancellationRequested)
+        {
+            // Driver.Modbus.Cli-005: Ctrl+C during InitializeAsync — exit quietly so CliFx
+            // does not render a full stack trace for a user-initiated cancellation.
+            await console.Output.WriteLineAsync("Cancelled.");
+        }
         finally
         {
             await driver.ShutdownAsync(CancellationToken.None);
         }
     }
+
+    /// <summary>
+    ///     Driver.Modbus.Cli-006: combine the driver-side <see cref="DriverState"/> with the
+    ///     probe snapshot's OPC UA <c>StatusCode</c> into a single headline verdict. Order
+    ///     of precedence:
+    ///     <list type="number">
+    ///       <item><c>FAIL</c> — driver did not reach <see cref="DriverState.Healthy"/>
+    ///         (Faulted / Reconnecting / Unknown) OR the snapshot reports Bad quality.</item>
+    ///       <item><c>DEGRADED</c> — driver Healthy but the snapshot quality is Uncertain.</item>
+    ///       <item><c>OK</c> — driver Healthy and snapshot Good.</item>
+    ///     </list>
+    /// </summary>
+    public static string ComputeVerdict(DriverState state, uint statusCode)
+    {
+        // OPC UA StatusCode top 2 bits encode the quality class:
+        //   0x00xxxxxx → Good, 0x40xxxxxx → Uncertain, 0x80xxxxxx / 0xC0xxxxxx → Bad.
+        var qualityClass = statusCode & 0xC0000000u;
+        var snapshotGood = qualityClass == 0x00000000u;
+        var snapshotUncertain = qualityClass == 0x40000000u;
+
+        if (state != DriverState.Healthy || !snapshotGood && !snapshotUncertain)
+            return $"FAIL (driver={state}, probe={SnapshotFormatter.FormatStatus(statusCode)})";
+
+        if (snapshotUncertain)
+            return $"DEGRADED (driver={state}, probe={SnapshotFormatter.FormatStatus(statusCode)})";
+
+        return $"OK (driver={state}, probe={SnapshotFormatter.FormatStatus(statusCode)})";
+    }
 }