fix(driver-s7-cli): resolve Low code-review findings (Driver.S7.Cli-004,005,006,007)

- Driver.S7.Cli-004: 'await using var driver' is the sole driver
  disposal path; dropped the redundant explicit await ShutdownAsync from
  each command's finally.
- Driver.S7.Cli-005: deleted the stale empty
  tests/ZB.MOM.WW.OtOpcUa.Driver.S7.Cli.Tests/ directory (the real test
  project lives under tests/Drivers/Cli/).
- Driver.S7.Cli-006: S7CommandBaseBuildOptionsTests cover the probe
  toggle, timeout mapping, host/port/CPU/rack/slot wiring, and tag list
  passthrough.
- Driver.S7.Cli-007: re-added the SubscribeCommand handler comment
  explaining the CliFx IConsole.Output usage and that the poll-thread
  raises events.

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

src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.S7.Cli/Commands/ProbeCommand.cs

@@ -33,6 +33,9 @@ public sealed class ProbeCommand : S7CommandBase
             Writable: false);
         var options = BuildOptions([probeTag]);
 
+        // Driver.S7.Cli-004: `await using` is the sole disposal mechanism — S7Driver.DisposeAsync
+        // already invokes ShutdownAsync, so the previous explicit ShutdownAsync(CancellationToken.None)
+        // call in a finally block ran shutdown twice. The await-using on the next line is enough.
         await using var driver = new S7Driver(options, DriverInstanceId);
         // Driver.S7.Cli-003: wrap the entire probe sequence so that a refused/unreachable TCP
         // connect still prints the structured Host/CPU/Health lines instead of crashing with a
@@ -66,9 +69,5 @@ public sealed class ProbeCommand : S7CommandBase
             if (health.LastError is { } err)
                 await console.Output.WriteLineAsync($"Last error:   {err}");
         }
-        finally
-        {
-            await driver.ShutdownAsync(CancellationToken.None);
-        }
     }
 }