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/DynamicBufferCapacity.cs

@@ -0,0 +1,30 @@
+namespace AcDream.App.Rendering;
+
+/// <summary>
+/// Capacity policy for render-thread-owned streaming GPU buffers. Dynamic
+/// buffers keep one backing allocation and update its active prefix; they do
+/// not orphan a new driver allocation on every draw call.
+/// </summary>
+internal static class DynamicBufferCapacity
+{
+    internal const int DefaultAlignment = 4096;
+
+    public static int Grow(int currentBytes, int requiredBytes, int alignment = DefaultAlignment)
+    {
+        if (currentBytes < 0)
+            throw new ArgumentOutOfRangeException(nameof(currentBytes));
+        if (requiredBytes < 0)
+            throw new ArgumentOutOfRangeException(nameof(requiredBytes));
+        if (alignment <= 0)
+            throw new ArgumentOutOfRangeException(nameof(alignment));
+        if (requiredBytes <= currentBytes)
+            return currentBytes;
+
+        long doubled = currentBytes == 0 ? alignment : (long)currentBytes * 2L;
+        long target = Math.Max(requiredBytes, doubled);
+        long aligned = ((target + alignment - 1L) / alignment) * alignment;
+        if (aligned > int.MaxValue)
+            throw new OverflowException("Dynamic GPU buffer capacity exceeds Int32.MaxValue.");
+        return (int)aligned;
+    }
+}