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/ResourceCleanupGroup.cs

@@ -0,0 +1,63 @@
+namespace AcDream.App.Rendering;
+
+/// <summary>
+/// Reverse-order, all-attempted cleanup owner used while a composite resource
+/// is still under construction and after it becomes the aggregate owner.
+/// </summary>
+internal sealed class ResourceCleanupGroup : IRetryableResourceCleanup
+{
+    private sealed record Entry(string Name, Action Release)
+    {
+        public bool Complete { get; set; }
+    }
+
+    private readonly List<Entry> _entries = [];
+    private bool _running;
+
+    public bool IsCleanupComplete => _entries.All(static entry => entry.Complete);
+
+    public void Add(string name, Action release)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(name);
+        ArgumentNullException.ThrowIfNull(release);
+        if (_running || IsCleanupComplete && _entries.Count != 0)
+            throw new InvalidOperationException("The resource cleanup group is no longer accepting ownership.");
+        _entries.Add(new Entry(name, release));
+    }
+
+    public void RetryCleanup()
+    {
+        if (_running || IsCleanupComplete)
+            return;
+
+        _running = true;
+        List<Exception>? failures = null;
+        try
+        {
+            for (int i = _entries.Count - 1; i >= 0; i--)
+            {
+                Entry entry = _entries[i];
+                if (entry.Complete)
+                    continue;
+                try
+                {
+                    entry.Release();
+                    entry.Complete = true;
+                }
+                catch (Exception failure)
+                {
+                    (failures ??= []).Add(new InvalidOperationException(
+                        $"Resource cleanup operation '{entry.Name}' failed.",
+                        failure));
+                }
+            }
+        }
+        finally
+        {
+            _running = false;
+        }
+
+        if (failures is not null)
+            throw new AggregateException("Composite resource cleanup remains incomplete.", failures);
+    }
+}