feat(entitlement): pivot to paid app ownership

Check Steam ownership of the paid app with BIsSubscribedApp; keep Debug fake ownership out of Release. Ref: https://partner.steamgames.com/doc/api/ISteamApps#BIsSubscribedApp

ViewModels/MainViewModel.OutputProfile.cs

@@ -4,44 +4,45 @@ using ytLive.Services.Entitlement;
 namespace ytLive.ViewModels;
 
 /// <summary>
-/// The entitlement surface: whether this session may emit output above the free budget.
+/// The app-wide Steam ownership flag and its output-profile consumer.
 ///
-/// <para>Deliberately a separate partial from <c>License.cs</c>: that file owns *how* a
-/// licence is validated (Polar today), this one owns *what the answer means* for output.
-/// Steam's DLC check and Polar's lease both collapse into <see cref="IsPremium"/>; nothing
-/// downstream of <see cref="HasProOutput"/> cares which one proved it.</para>
+/// <para>Only the entitlement service decides whether the current Steam account owns the paid app.
+/// Development builds use a fake owned result; Release builds use Steam.</para>
 /// </summary>
 public partial class MainViewModel
 {
-    /// <summary>
-    /// The single input to <see cref="Models.OutputProfile.Resolve"/>.
-    ///
-    /// <para><b>Fail closed:</b> an unresolved or unreadable licence is simply false, so a
-    /// build with no entitlement emits the free profile. There is no "unknown" branch to get
-    /// wrong.</para>
-    ///
-    /// <para><b>Developer mode never ships:</b> <see cref="DeveloperMode"/> is only ever
-    /// settable inside a development build (see <see cref="DevBuild"/>), so this expression
-    /// reduces to <c>IsPremium</c> in a Release binary.</para>
-    /// </summary>
-    public bool HasProOutput => IsPremium || DeveloperMode || _entitlement.IsPro;
+    private IEntitlement _entitlement = CreateEntitlement();
+    private bool _isAppOwned;
 
-    /// <summary>
-    /// The entitlement rail for this session. Lifetime = Steam DLC; until the DLC app id exists it
-    /// is <see cref="SteamEntitlement.NotConfigured"/>, which reads false (fail closed). Tests
-    /// inject a fake through <see cref="EntitlementOverride"/>.
-    /// </summary>
-    private IEntitlement _entitlement = SteamEntitlement.NotConfigured();
+    public bool IsAppOwned
+    {
+        get => _isAppOwned;
+        private set
+        {
+            if (!SetProperty(ref _isAppOwned, value)) return;
+            OnPropertyChanged(nameof(HasProOutput));
+        }
+    }
 
-    /// <summary>Test seam: swap the rail without a Steam client. Internal — the test assembly is
-    /// the only caller, and a public setter here would be a licence bypass surface.</summary>
+    public bool HasProOutput => DeveloperMode || IsAppOwned;
+
+    private static IEntitlement CreateEntitlement()
+    {
+#if DEBUG
+        return new FakeEntitlement(true);
+#else
+        return SteamEntitlement.NotConfigured();
+#endif
+    }
+
+    /// <summary>Test seam: swap the ownership source without a Steam client.</summary>
     internal IEntitlement EntitlementOverride
     {
         get => _entitlement;
         set
         {
             _entitlement = value;
-            OnPropertyChanged(nameof(HasProOutput));
+            IsAppOwned = value.IsAppOwned;
         }
     }
 

ViewModels/MainViewModel.cs

@@ -192,6 +192,7 @@ public partial class MainViewModel : ViewModelBase
     public MainViewModel()
     {
         AppLog.Write("MainViewModel ctor begin");
+        IsAppOwned = _entitlement.IsAppOwned;
         _youtubeAuth = new YouTubeAuthService(OAuthCredentials.ClientId, OAuthCredentials.ClientSecret,
             sessionChanged: ch => TokenStore.Save(ch));
         _youtubeStream = new YouTubeStreamService(_youtubeAuth);