create_graphics_pipeline now destroys its shader modules on the error
path as well, and update_mesh nulls the buffer handles after destroying
them so a later Drop or retry cannot redestroy freed buffers.
Replace ptr::read-based field consumption with Option<T> + take() for
sync primitives, GPU allocations, and the allocator itself. The prior
pattern left bitwise-duplicated values in the original fields, so Rust's
automatic field drop after Drop::drop returned freed the same heap
buffers (Vec backings inside SyncPrimitives) and Allocations twice.
The allocator is now explicitly dropped before destroy_device so its
own Drop impl, which releases vk::DeviceMemory blocks, runs while the
logical device is still valid. Swapchain image views are also now
destroyed before the swapchain, as required by the Vulkan spec.
Serkyo