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/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests/ModbusSimulatorFixture.cs

@@ -36,10 +36,16 @@ public sealed class ModbusSimulatorFixture : IAsyncDisposable
     private const string DefaultEndpoint = "10.100.0.35:5020";
     private const string EndpointEnvVar = "MODBUS_SIM_ENDPOINT";
 
+    /// <summary>Gets the host address of the Modbus simulator.</summary>
     public string Host { get; }
+
+    /// <summary>Gets the port of the Modbus simulator.</summary>
     public int Port { get; }
+
+    /// <summary>Gets the skip reason if the simulator is unreachable; otherwise null.</summary>
     public string? SkipReason { get; }
 
+    /// <summary>Initializes a new instance of the <see cref="ModbusSimulatorFixture"/> class.</summary>
     public ModbusSimulatorFixture()
     {
         var raw = Environment.GetEnvironmentVariable(EndpointEnvVar) ?? DefaultEndpoint;
@@ -76,6 +82,7 @@ public sealed class ModbusSimulatorFixture : IAsyncDisposable
         }
     }
 
+    /// <inheritdoc />
     public ValueTask DisposeAsync() => ValueTask.CompletedTask;
 }