fix(rendering): bound portal resource lifetime

Separate logical ownership, render publication, and GPU retirement across live entities, landblocks, particles, textures, mesh arenas, portal/UI teardown, and per-frame scratch storage. Add bounded DAT/texture caches, upload budgets, three-frame fence retirement, exact-incarnation appearance reconciliation, frame pacing, and extensive lifetime conformance coverage.\n\nThe seven-destination connected route now cuts peak working/private memory roughly in half, returns Caul to 125-153 FPS locally, and produces no WER or AMD reset.\n\nCo-authored-by: OpenAI Codex <codex@openai.com>

src/AcDream.App/Rendering/OwnerScopedResourceRegistry.cs

@@ -0,0 +1,61 @@
+namespace AcDream.App.Rendering;
+
+/// <summary>
+/// Tracks shared resources by logical owner. Repeated use of the same key by
+/// one owner is idempotent; a key is returned for destruction only after its
+/// final owner leaves. Render-thread only.
+/// </summary>
+internal sealed class OwnerScopedResourceRegistry<TKey> where TKey : notnull
+{
+    private readonly Dictionary<uint, HashSet<TKey>> _keysByOwner = new();
+    private readonly Dictionary<TKey, int> _ownerCountByKey = new();
+
+    public int OwnerCount => _keysByOwner.Count;
+    public int ResourceCount => _ownerCountByKey.Count;
+
+    public bool Acquire(uint ownerId, TKey key)
+    {
+        if (ownerId == 0)
+            throw new ArgumentOutOfRangeException(nameof(ownerId));
+
+        if (!_keysByOwner.TryGetValue(ownerId, out HashSet<TKey>? keys))
+        {
+            keys = new HashSet<TKey>();
+            _keysByOwner.Add(ownerId, keys);
+        }
+
+        if (!keys.Add(key))
+            return false;
+
+        _ownerCountByKey[key] = _ownerCountByKey.GetValueOrDefault(key) + 1;
+        return true;
+    }
+
+    public IReadOnlyList<TKey> ReleaseOwner(uint ownerId)
+    {
+        if (!_keysByOwner.Remove(ownerId, out HashSet<TKey>? keys))
+            return Array.Empty<TKey>();
+
+        List<TKey>? unowned = null;
+        foreach (TKey key in keys)
+        {
+            int remaining = _ownerCountByKey[key] - 1;
+            if (remaining > 0)
+            {
+                _ownerCountByKey[key] = remaining;
+                continue;
+            }
+
+            _ownerCountByKey.Remove(key);
+            (unowned ??= new List<TKey>()).Add(key);
+        }
+
+        return unowned is null ? Array.Empty<TKey>() : unowned;
+    }
+
+    public void Clear()
+    {
+        _keysByOwner.Clear();
+        _ownerCountByKey.Clear();
+    }
+}