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/Core/ZB.MOM.WW.OtOpcUa.Core.Tests/Resilience/InFlightCounterTests.cs

@@ -8,6 +8,7 @@ namespace ZB.MOM.WW.OtOpcUa.Core.Tests.Resilience;
 [Trait("Category", "Unit")]
 public sealed class InFlightCounterTests
 {
+    /// <summary>Verifies that starting and completing a call nets to zero.</summary>
     [Fact]
     public void StartThenComplete_NetsToZero()
     {
@@ -18,6 +19,7 @@ public sealed class InFlightCounterTests
         tracker.TryGet("drv", "host-a")!.CurrentInFlight.ShouldBe(0);
     }
 
+    /// <summary>Verifies that nested starts sum the depth.</summary>
     [Fact]
     public void NestedStarts_SumDepth()
     {
@@ -32,6 +34,7 @@ public sealed class InFlightCounterTests
         tracker.TryGet("drv", "host-a")!.CurrentInFlight.ShouldBe(2);
     }
 
+    /// <summary>Verifies that completing before start is clamped to zero.</summary>
     [Fact]
     public void CompleteBeforeStart_ClampedToZero()
     {
@@ -42,6 +45,7 @@ public sealed class InFlightCounterTests
         tracker.TryGet("drv", "host-a")!.CurrentInFlight.ShouldBe(0);
     }
 
+    /// <summary>Verifies that different hosts track independently.</summary>
     [Fact]
     public void DifferentHosts_TrackIndependently()
     {
@@ -54,6 +58,7 @@ public sealed class InFlightCounterTests
         tracker.TryGet("drv", "host-b")!.CurrentInFlight.ShouldBe(1);
     }
 
+    /// <summary>Verifies that concurrent starts do not lose count.</summary>
     [Fact]
     public void ConcurrentStarts_DoNotLose_Count()
     {
@@ -63,6 +68,7 @@ public sealed class InFlightCounterTests
         tracker.TryGet("drv", "host-a")!.CurrentInFlight.ShouldBe(500);
     }
 
+    /// <summary>Verifies that CapabilityInvoker increments the tracker during execution.</summary>
     [Fact]
     public async Task CapabilityInvoker_IncrementsTracker_DuringExecution()
     {
@@ -90,6 +96,7 @@ public sealed class InFlightCounterTests
         tracker.TryGet("drv-live", "plc-1")!.CurrentInFlight.ShouldBe(0, "post-call, counter decremented");
     }
 
+    /// <summary>Verifies that CapabilityInvoker decrements the counter on exception.</summary>
     [Fact]
     public async Task CapabilityInvoker_ExceptionPath_DecrementsCounter()
     {
@@ -111,6 +118,7 @@ public sealed class InFlightCounterTests
             "finally-block must decrement even when call-site throws");
     }
 
+    /// <summary>Verifies that CapabilityInvoker without a tracker does not throw.</summary>
     [Fact]
     public async Task CapabilityInvoker_WithoutTracker_DoesNotThrow()
     {