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.Core/Content/IDatObjectSource.cs

@@ -0,0 +1,21 @@
+using DatReaderWriter.Lib.IO;
+using System.Diagnostics.CodeAnalysis;
+
+namespace AcDream.Core.Content;
+
+/// <summary>
+/// Minimal typed DAT-object lookup seam used by Core algorithms.
+/// </summary>
+/// <remarks>
+/// Core deliberately does not own DAT file handles or caching policy. The App
+/// runtime supplies the bounded Content-layer implementation; tests and
+/// short-lived tools may adapt another source explicitly.
+/// </remarks>
+public interface IDatObjectSource
+{
+    [return: MaybeNull]
+    T Get<T>(uint fileId) where T : IDBObj;
+
+    bool TryGet<T>(uint fileId, [MaybeNullWhen(false)] out T value)
+        where T : IDBObj;
+}