Refactor: remove HttpExtensions and inline HTTP method mapping

Removed HttpExtensions.cs and its extension methods for RestType-to-HttpMethod conversion. Introduced a private static CreateHttpRequestMessage method in InvokeRecActionViewCommandHandler to handle HTTP method mapping and request creation directly, reducing indirection and simplifying dependencies.

src/ReC.Application/RecActions/Commands/InvokeRecActionViewCommand.cs

@@ -38,9 +38,7 @@ public class InvokeRecActionViewCommandHandler(
                 $"Id: {action.Id}"
             );
 
-        using var httpReq = restType
-            .ToHttpMethod()
-            .ToHttpRequestMessage(action.EndpointUri);
+        using var httpReq = CreateHttpRequestMessage(restType, action.EndpointUri);
 
         if (action.Body is not null)
             httpReq.Content = new StringContent(action.Body);
@@ -136,4 +134,24 @@ public class InvokeRecActionViewCommandHandler(
 
         return response.IsSuccessStatusCode;
     }
+
+    private static HttpRequestMessage CreateHttpRequestMessage(RestType restType, string? endpointUri)
+    {
+        var method = restType switch
+        {
+            RestType.Get => HttpMethod.Get,
+            RestType.Post => HttpMethod.Post,
+            RestType.Put => HttpMethod.Put,
+            RestType.Delete => HttpMethod.Delete,
+            RestType.Patch => HttpMethod.Patch,
+            RestType.Head => HttpMethod.Head,
+            RestType.Options => HttpMethod.Options,
+            RestType.Trace => HttpMethod.Trace,
+            RestType.Connect => HttpMethod.Connect,
+            RestType.None => throw new ArgumentOutOfRangeException(nameof(restType), $"The RestType value '{restType}' is not valid."),
+            _ => new HttpMethod(restType.ToString().ToUpperInvariant())
+        };
+
+        return new HttpRequestMessage(method, endpointUri);
+    }
 }