feat(client): send X-Stainless-Lang and X-Stainless-OS headers

Author: stainless-app[bot]

src/Orb/Core/ParamsBase.cs

@@ -163,6 +163,8 @@ protected string QueryString(ClientOptions options)
     protected static void AddDefaultHeaders(HttpRequestMessage request, ClientOptions options)
     {
         request.Headers.Add("X-Stainless-Arch", GetOSArch());
+        request.Headers.Add("X-Stainless-Lang", "csharp");
+        request.Headers.Add("X-Stainless-OS", GetOS());
 
         if (options.APIKey != null)
         {
@@ -183,4 +185,21 @@ or Architecture.LoongArch64
             or Architecture.Ppc64le => $"other:{RuntimeInformation.OSArchitecture}",
             _ => "unknown",
         };
+
+    static string GetOS()
+    {
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+        {
+            return "Windows";
+        }
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+        {
+            return "MacOS";
+        }
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+        {
+            return "Linux";
+        }
+        return $"Other:{RuntimeInformation.OSDescription}";
+    }
 }