test(runtime): de-flake the hung-write release test; name the real write bound

The fixture wedged EVERY write on one shared token-ignoring release gate, so
the later same-tag write was also hung, and the 300 ms pessimistic bound
abandoned it while the test was still polling before ReleaseWrites(). Its
reason was "write did not complete within" (the bound), not "queued for" (the
queue budget), and it had already entered the driver, so the tag had been
released. The release path is correct. Only the first write now hangs, and
later writes complete at once.

The abandon reason formatted the bound with TotalSeconds:F0, which printed a
300 ms bound as "0s". It now uses milliseconds, and the test asserts it.

Refs #731

Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/Drivers/DriverInstanceActor.cs

@@ -1170,7 +1170,7 @@ public sealed class DriverInstanceActor : ReceiveActor, IWithTimers
                 try { cts.Cancel(); } catch (ObjectDisposedException) { }
                 _ = attempt.ContinueWith(t => _ = t.Exception, TaskContinuationOptions.OnlyOnFaulted);
                 replyTo.Tell(new WriteAttributeResult(false,
-                    $"StatusCode=0x800A0000 (BadTimeout: write did not complete within {writeTimeout.TotalSeconds:F0}s)"));
+                    $"StatusCode=0x800A0000 (BadTimeout: write did not complete within {writeTimeout.TotalMilliseconds:F0} ms)"));
                 return;
             }
             if (results is { Count: 1 } && IsGoodStatus(results[0].StatusCode))