perf(decompress): release compressed staging after submit, not for the resource's life

The compressed Mesh::Build / ImageVulkan::Update paths kept their host-visible
`compressedStaging` (holding the GDeflate streams) alive for the whole life of
the mesh/image, pinning host-visible memory long after the single GPU decompress
that reads it has retired.

Release it via VulkanBuffer::DeferredClear() right after recording the decompress.
The recorded vkCmdDecompressMemoryEXT still references compressedStaging.address,
so it must outlive the submit — exactly what the fence-keyed deletion queue
(#101/#102) guarantees: it retires the allocation only after framesInFlight frames
have elapsed, by which point the submit's fence has cleared. Between Builds/Updates
the handle is null; the next call's Resize re-creates it.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

implementations/Crafter.Graphics-Mesh.cpp

@@ -261,6 +261,16 @@ void Mesh::Build(const CompressedMeshAsset& asset, VkCommandBuffer cmd, RTBuildO
         VK_PIPELINE_STAGE_2_ACCELERATION_STRUCTURE_BUILD_BIT_KHR,
         VK_ACCESS_2_ACCELERATION_STRUCTURE_READ_BIT_KHR);
 
+    // The compressed staging is only read by the decompress recorded above; the
+    // subsequent BLAS build reads the decompressed vertex/index buffers, never
+    // this. So hand it to the fence-keyed deletion queue (#101/#102) now rather
+    // than pinning host-visible memory for the mesh's whole life. The recorded
+    // vkCmdDecompressMemoryEXT still references compressedStaging.address, so it
+    // must outlive this submit — which the queue guarantees: it retires the
+    // allocation only after framesInFlight frames have elapsed, by which point
+    // the decompress submit's fence has cleared.
+    compressedStaging.DeferredClear();
+
     allowUpdate     = options.allowUpdate;
     builtInputCount = asset.vertexCount;
     RecordBLASBuild(*this, asset.vertexCount, asset.indexCount, BlasFlags(options), /*update*/ false, cmd);

interfaces/Crafter.Graphics-ImageVulkan.cppm

@@ -75,9 +75,12 @@ export namespace Crafter {
         VkImage image;
         VkDeviceMemory imageMemory;
         VulkanBuffer<PixelType, true> buffer;
-        // Lives until the compressed Update path's cmd buffer completes.
+        // Transient host-visible staging for the compressed Update path. Same
-        // Same lifetime contract as Mesh::compressedStaging — caller must
+        // lifetime contract as Mesh::compressedStaging: the compressed Update
-        // not destroy / re-Update before the submit fence is signaled.
+        // releases it via DeferredClear() right after recording the decompress,
+        // so the fence-keyed deletion queue (#101/#102) frees it once that
+        // submit's frame has cleared instead of pinning it for the image's life.
+        // Between Updates the handle is null; the next Update's Resize re-creates it.
         VulkanBuffer<std::byte, true> compressedStaging;
         VkImageView imageView;
         VkDescriptorImageInfo descriptor;
@@ -299,6 +302,16 @@ export namespace Crafter {
                 VK_PIPELINE_STAGE_2_COPY_BIT,
                 VK_ACCESS_2_TRANSFER_READ_BIT);
 
+            // Compressed staging is read only by the decompress recorded above;
+            // the buffer→image copy below reads `buffer` (the decompress dst),
+            // never this. Release it to the fence-keyed deletion queue
+            // (#101/#102) now instead of pinning host-visible memory for the
+            // image's whole life. The recorded vkCmdDecompressMemoryEXT still
+            // references compressedStaging.address, so it must outlive this
+            // submit — which the queue guarantees by retiring the allocation
+            // only after framesInFlight frames (i.e. after the submit's fence).
+            compressedStaging.DeferredClear();
+
             // Continue with the existing buffer→image upload + layout transitions.
             // We've already inserted the decompress→transfer-read barrier,
             // so we skip the FlushDevice host-write barrier the regular Update

interfaces/Crafter.Graphics-Mesh.cppm

@@ -77,12 +77,13 @@ export namespace Crafter {
         // Lifetime contract matches vertexBuffer/indexBuffer: must stay
         // alive until the build submitted on `cmd` completes.
         VulkanBuffer<RTAabb, true> aabbBuffer;
-        // Lives until the cmd buffer issued by the compressed Build path
+        // Transient host-visible staging for the compressed Build path. Kept as
-        // completes execution. Kept as a member so the recorded
+        // a member only so the recorded vkCmdDecompressMemoryEXT has a stable
-        // vkCmdDecompressMemoryEXT references valid memory until the queue
+        // address to reference; the compressed Build releases it via
-        // submit signals — caller must not re-Build or destroy the Mesh
+        // DeferredClear() right after recording the decompress, so it is freed
-        // before that submit's fence is signaled (same contract as the
+        // by the fence-keyed deletion queue (#101/#102) once that submit's frame
-        // existing uncompressed path).
+        // has cleared — no longer pinned for the mesh's life. Between Builds the
+        // handle is null; the next Build's Resize re-creates it.
         VulkanBuffer<std::byte, true> compressedStaging;
         VkAccelerationStructureGeometryTrianglesDataKHR blasData;
         VkAccelerationStructureGeometryKHR blas;