- Replace gpu-allocator with vk-mem 0.5.0 (VMA 3.3.0) in renderer_device
- Add public GpuAllocation wrapper, MemoryLocation, AllocationDesc, and
allocate_for_buffer/image + bind_buffer/image_memory helpers
- Restrict CPU-mapped allocations to HOST_VISIBLE|HOST_COHERENT memory types
- Handle guards: raw buffer/image handles owned before allocation so failure
paths never leak
- Use renderer_device::device::MemoryLocation across renderer, renderer_resources,
and renderer_rendergraph; remove all gpu-allocator dependencies
- Error on dedicated allocation below Vulkan 1.1 instead of silent downgrade
- Add Send/Sync asserts, coherent-mapping and dedicated-allocation validation
tests; update AGENTS.md docs
janis