fix(driver-twincat): resolve Low code-review findings (Driver.TwinCAT-004,006,014,015,016)

- Driver.TwinCAT-004: corrected the IEC time-type inline comments;
  documented that the driver currently surfaces them as raw UInt32
  counters.
- Driver.TwinCAT-006: ResolveHost returns a documented UnresolvedHost
  sentinel when no devices are configured instead of returning the
  logical DriverInstanceId (which never matches GetHostStatuses).
- Driver.TwinCAT-014: wired Probe.Timeout into the probe-loop call and
  added a NotificationMaxDelayMs config knob threaded through
  AddNotificationAsync.
- Driver.TwinCAT-015: Dispose() runs a genuinely synchronous teardown
  with bounded waits (no sync-over-async deadlock pattern).
- Driver.TwinCAT-016: pinned the Structure-tag rejection and the
  probe-loop vs read disposal race with regression tests.

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

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT.Tests/FakeTwinCATClient.cs

@@ -67,14 +67,17 @@ internal class FakeTwinCATClient : ITwinCATClient
 
     public List<FakeNotification> Notifications { get; } = new();
     public bool ThrowOnAddNotification { get; set; }
+    /// <summary>Records the most recently-supplied <c>maxDelayMs</c> for Driver.TwinCAT-014 tests.</summary>
+    public int LastMaxDelayMs { get; private set; }
 
     public virtual Task<ITwinCATNotificationHandle> AddNotificationAsync(
         string symbolPath, TwinCATDataType type, int? bitIndex, TimeSpan cycleTime,
-        Action<string, object?> onChange, CancellationToken cancellationToken)
+        int maxDelayMs, Action<string, object?> onChange, CancellationToken cancellationToken)
     {
         if (ThrowOnAddNotification)
             throw Exception ?? new InvalidOperationException("fake AddNotification failure");
 
+        LastMaxDelayMs = maxDelayMs;
         var reg = new FakeNotification(symbolPath, type, bitIndex, onChange, this);
         Notifications.Add(reg);
         return Task.FromResult<ITwinCATNotificationHandle>(reg);