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/BindlessTextureMutationGuard.cs

@@ -0,0 +1,68 @@
+using System.Runtime.ExceptionServices;
+
+namespace AcDream.App.Rendering;
+
+/// <summary>
+/// Temporarily removes bindless residency around texture-state mutation while
+/// retaining the obligation to restore the pair across failed mutation or
+/// failed reacquisition attempts.
+/// </summary>
+internal sealed class BindlessTextureMutationGuard(BindlessTexturePair pair)
+{
+    private bool _restoreRequired;
+    private bool _operationActive;
+
+    internal bool RestoreRequired => _restoreRequired;
+
+    public void Execute(Action mutation)
+    {
+        ArgumentNullException.ThrowIfNull(mutation);
+        if (_operationActive)
+            throw new InvalidOperationException("A bindless texture mutation is already active.");
+
+        _operationActive = true;
+        Exception? mutationFailure = null;
+        Exception? restoreFailure = null;
+        try
+        {
+            _restoreRequired |= pair.HasAnyResident;
+            if (pair.HasAnyResident)
+                pair.Release();
+
+            mutation();
+        }
+        catch (Exception failure)
+        {
+            mutationFailure = failure;
+        }
+        finally
+        {
+            if (_restoreRequired)
+            {
+                try
+                {
+                    _ = pair.Acquire();
+                    _restoreRequired = false;
+                }
+                catch (Exception failure)
+                {
+                    restoreFailure = failure;
+                }
+            }
+
+            _operationActive = false;
+        }
+
+        if (mutationFailure is not null && restoreFailure is not null)
+        {
+            throw new AggregateException(
+                "Texture-state mutation failed and bindless residency could not be restored.",
+                mutationFailure,
+                restoreFailure);
+        }
+        if (mutationFailure is not null)
+            ExceptionDispatchInfo.Capture(mutationFailure).Throw();
+        if (restoreFailure is not null)
+            ExceptionDispatchInfo.Capture(restoreFailure).Throw();
+    }
+}