Resolve DA, A&C, and security spec gaps with ServerCapabilities, alarm methods, and modern profiles

Add ServerCapabilities/OperationLimits node, enable diagnostics, add OnModifyMonitoredItemsComplete
override for DA compliance. Wire shelving, enable/disable, confirm, and addcomment handlers on
alarm conditions with LocalTime/Quality event fields for Part 9 compliance. Add Aes128/Aes256
security profiles, X.509 certificate authentication, and AUDIT-prefixed auth logging. Fix flaky
probe monitor test. Update docs for all changes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/ZB.MOM.WW.LmxOpcUa.Tests/MxAccess/MxAccessClientMonitorTests.cs

@@ -120,7 +120,7 @@ namespace ZB.MOM.WW.LmxOpcUa.Tests.MxAccess
             var config = new MxAccessConfiguration
             {
                 ProbeTag = "TestProbe",
-                ProbeStaleThresholdSeconds = 2,
+                ProbeStaleThresholdSeconds = 5,
                 MonitorIntervalSeconds = 1,
                 AutoReconnect = true
             };
@@ -130,6 +130,7 @@ namespace ZB.MOM.WW.LmxOpcUa.Tests.MxAccess
             client.StartMonitor();
 
             // Continuously simulate probe data changes to keep it fresh
+            // Stale threshold (5s) is well above the delay (500ms) to avoid timing flakes
             for (var i = 0; i < 8; i++)
             {
                 await Task.Delay(500);