refactor(lifetime): own render resource prefixes

Give terrain, sky, retained UI, portal preparation, and the update/render frame pair explicit single owners. Make shader, texture, text, bindless, and GL construction prefixes checked and retryable so partial failure cannot lose or replay resource ownership.

Co-authored-by: Codex <codex@openai.com>

src/AcDream.App/Rendering/GameFrameGraphSlot.cs

@@ -0,0 +1,67 @@
+using AcDream.App.Update;
+
+namespace AcDream.App.Rendering;
+
+internal interface IGameUpdateFrameRoot
+{
+    void Tick(UpdateFrameInput input);
+}
+
+internal interface IGameRenderFrameRoot
+{
+    RenderFrameOutcome Render(RenderFrameInput input);
+}
+
+/// <summary>
+/// Sole atomic publication point for the current update/render frame pair.
+/// Native callbacks are deliberately inert before publication and after
+/// withdrawal so a partial load or converging shutdown cannot enter half a
+/// frame graph.
+/// </summary>
+internal sealed class GameFrameGraphSlot
+{
+    private sealed record FrameGraphPair(
+        IGameUpdateFrameRoot Update,
+        IGameRenderFrameRoot Render);
+
+    private FrameGraphPair? _pair;
+
+    public bool IsPublished => Volatile.Read(ref _pair) is not null;
+
+    public void Publish(IGameUpdateFrameRoot update, IGameRenderFrameRoot render)
+    {
+        ArgumentNullException.ThrowIfNull(update);
+        ArgumentNullException.ThrowIfNull(render);
+        var pair = new FrameGraphPair(update, render);
+        if (Interlocked.CompareExchange(ref _pair, pair, null) is not null)
+            throw new InvalidOperationException("A game frame graph is already published.");
+    }
+
+    public bool Tick(UpdateFrameInput input)
+    {
+        FrameGraphPair? pair = Volatile.Read(ref _pair);
+        if (pair is null)
+            return false;
+
+        pair.Update.Tick(input);
+        return true;
+    }
+
+    public bool Render(RenderFrameInput input, out RenderFrameOutcome outcome)
+    {
+        FrameGraphPair? pair = Volatile.Read(ref _pair);
+        if (pair is null)
+        {
+            outcome = default;
+            return false;
+        }
+
+        outcome = pair.Render.Render(input);
+        return true;
+    }
+
+    public void Withdraw()
+    {
+        Interlocked.Exchange(ref _pair, null);
+    }
+}