docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/SdkAddressSpaceSinkTests.cs

@@ -19,6 +19,7 @@ public sealed class SdkAddressSpaceSinkTests : IDisposable
         Path.GetTempPath(),
         $"otopcua-sink-{Guid.NewGuid():N}");
 
+    /// <summary>Verifies that WriteValue creates and updates variables in the OPC UA node manager.</summary>
     [Fact]
     public async Task WriteValue_creates_and_updates_variable_in_node_manager()
     {
@@ -34,6 +35,7 @@ public sealed class SdkAddressSpaceSinkTests : IDisposable
         await host.DisposeAsync();
     }
 
+    /// <summary>Verifies that WriteAlarmState creates a dedicated node distinct from value writes.</summary>
     [Fact]
     public async Task WriteAlarmState_creates_dedicated_node_distinct_from_value_writes()
     {
@@ -48,6 +50,7 @@ public sealed class SdkAddressSpaceSinkTests : IDisposable
         await host.DisposeAsync();
     }
 
+    /// <summary>Verifies that RebuildAddressSpace clears all registered variables.</summary>
     [Fact]
     public async Task RebuildAddressSpace_clears_all_registered_variables()
     {
@@ -69,6 +72,7 @@ public sealed class SdkAddressSpaceSinkTests : IDisposable
         await host.DisposeAsync();
     }
 
+    /// <summary>Verifies that NullOpcUaAddressSpaceSink does not crash on any call.</summary>
     [Fact]
     public async Task NullOpcUaAddressSpaceSink_does_not_crash_on_any_call()
     {
@@ -108,6 +112,7 @@ public sealed class SdkAddressSpaceSinkTests : IDisposable
         return port;
     }
 
+    /// <summary>Cleans up the PKI root directory.</summary>
     public void Dispose()
     {
         if (Directory.Exists(_pkiRoot))