fix(common): classify request cancellation in profiler

Preserve legacy profiler contracts and record expected cancellation below error level.

HrynCo.Common/Profiler.cs

@@ -6,12 +6,26 @@ using Serilog;
 public interface IProfiler
 {
     Task<T> MeasureExecutionAsync<T>(Func<Task<T>> function, string blockName = "");
+    Task<T> MeasureExecutionAsync<T>(Func<Task<T>> function, string blockName, CancellationToken cancellationToken)
+    {
+        return MeasureExecutionAsync(function, blockName);
+    }
+
     Task MeasureExecutionAsync(Func<Task> action, string blockName = "");
+    Task MeasureExecutionAsync(Func<Task> action, string blockName, CancellationToken cancellationToken)
+    {
+        return MeasureExecutionAsync(action, blockName);
+    }
 }
 
 public class Profiler(ILogger logger) : IProfiler
 {
-    public async Task<T> MeasureExecutionAsync<T>(Func<Task<T>> function, string blockName = "")
+    public Task<T> MeasureExecutionAsync<T>(Func<Task<T>> function, string blockName = "")
+    {
+        return MeasureExecutionAsync(function, blockName, CancellationToken.None);
+    }
+
+    public async Task<T> MeasureExecutionAsync<T>(Func<Task<T>> function, string blockName, CancellationToken cancellationToken)
     {
         logger.ForContext("PerformanceLog", true).Information("{BlockName} - Start", blockName);
 
@@ -42,6 +56,13 @@ public class Profiler(ILogger logger) : IProfiler
 
             return result;
         }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            logger
+                .ForContext("PerformanceLog", true)
+                .Debug("{BlockName} - Canceled", blockName);
+            throw;
+        }
         catch (Exception ex) // NOSONAR
         {
             logger
@@ -51,12 +72,17 @@ public class Profiler(ILogger logger) : IProfiler
         }
     }
 
-    public async Task MeasureExecutionAsync(Func<Task> action, string blockName = "")
+    public Task MeasureExecutionAsync(Func<Task> action, string blockName = "")
+    {
+        return MeasureExecutionAsync(action, blockName, CancellationToken.None);
+    }
+
+    public async Task MeasureExecutionAsync(Func<Task> action, string blockName, CancellationToken cancellationToken)
     {
         await MeasureExecutionAsync<object?>(async () =>
         {
             await action();
             return null;
-        }, blockName);
+        }, blockName, cancellationToken);
     }
-}
+}

HrynCo.Common/README.md

@@ -11,6 +11,20 @@ Shared common utilities for HrynCo applications.
 - Tree traversal helpers
 - Time and profiling helpers
 
+## Profiling and cancellation
+
+`IProfiler.MeasureExecutionAsync` supports both result-returning and action delegates. Existing overloads keep their original behavior. Pass a cancellation token as the third argument when profiling work associated with a request:
+
+```csharp
+await profiler.MeasureExecutionAsync(() => LoadItemsAsync(cancellationToken), "LoadItems", cancellationToken);
+```
+
+If the delegate throws `OperationCanceledException` (including `TaskCanceledException`) and the supplied token is canceled, the profiler writes a Debug cancellation event with `PerformanceLog = true` and no attached exception, then rethrows the original exception. An `OperationCanceledException` with an uncanceled or absent token, and any other exception even with a canceled token, remain Error events with the exception attached. Failed or canceled operations do not write a successful End measurement.
+
+The supplied token controls log classification; the caller must pass it to the operation itself. The profiler does not cancel the delegate or reject successful work when the token is canceled.
+
+Custom implementations of `IProfiler` that implement only the original overloads remain compatible. The new interface overloads default to the original methods; custom implementations must override them to add token-aware log classification.
+
 ## Packaging
 
 This package is intended for reuse through NuGet. The test project is excluded from packing.