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/World/LandblockStaticEntityIdAllocator.cs

@@ -0,0 +1,36 @@
+namespace AcDream.Core.World;
+
+/// <summary>
+/// Allocates stable, collision-free local ids for dat-authored
+/// <c>LandBlockInfo.Objects</c> and building shells.
+/// </summary>
+/// <remarks>
+/// The top nibble is fixed at <c>0xC</c>. The remaining 28 bits encode the
+/// complete landblock X byte, Y byte, and a 12-bit per-landblock counter:
+/// <c>0xCXXYYIII</c>. The former <c>0xC0XXYYII</c> packing had only eight
+/// counter bits, so a legitimate dense retail landblock aborted after 255
+/// entries and was retried every time it streamed into view.
+/// </remarks>
+public static class LandblockStaticEntityIdAllocator
+{
+    public const uint MaxCounter = 0xFFFu;
+
+    public static uint Base(uint landblockX, uint landblockY) =>
+        0xC0000000u
+        | ((landblockX & 0xFFu) << 20)
+        | ((landblockY & 0xFFu) << 12);
+
+    public static uint Allocate(uint landblockX, uint landblockY, ref uint counter)
+    {
+        if (counter > MaxCounter)
+        {
+            throw new InvalidDataException(
+                $"Landblock ({landblockX & 0xFFu:X2},{landblockY & 0xFFu:X2}) exceeds the 4096-entry static entity id namespace.");
+        }
+
+        return Base(landblockX, landblockY) + counter++;
+    }
+
+    public static bool IsInNamespace(uint entityId) =>
+        (entityId & 0xF0000000u) == 0xC0000000u;
+}