feat(entitlement): gate 60 fps output through Steam

ytLive.Tests/EntitlementTests.cs

@@ -20,7 +20,9 @@ public class EntitlementTests
     [Fact]
     public void No_configured_paid_app_id_reads_as_not_owned()
     {
-        Assert.False(SteamEntitlement.NotConfigured().IsAppOwned);
+        var entitlement = SteamEntitlement.NotConfigured();
+        Assert.False(entitlement.IsAppOwned);
+        Assert.Contains("paid Steam app ID is not configured", entitlement.ErrorMessage);
     }
 
     [Fact]
@@ -40,6 +42,7 @@ public class EntitlementTests
 
         Assert.True(entitlement.IsAppOwned);
         Assert.Equal(paidAppId, queriedAppId);
+        Assert.Null(entitlement.ErrorMessage);
     }
 
     [Fact]
@@ -47,6 +50,16 @@ public class EntitlementTests
     {
         var entitlement = new SteamEntitlement(1234567u, () => false, _ => true, () => { });
         Assert.False(entitlement.IsAppOwned);
+        Assert.Contains("Open Steam", entitlement.ErrorMessage);
+    }
+
+    [Fact]
+    public void A_valid_steam_check_for_an_unowned_account_is_not_an_authentication_error()
+    {
+        var entitlement = new SteamEntitlement(1234567u, () => true, _ => false, () => { });
+
+        Assert.False(entitlement.IsAppOwned);
+        Assert.Null(entitlement.ErrorMessage);
     }
 
     [Fact]