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>