Fix vkCmdCopyBuffer SYNC-HAZARD-WRITE-AFTER-WRITE error

[TP-David]

These errors appear when enabling "Synchronization" Layer Configuration in Vulkan Configurator and running vsgtext:

Validation Error: [ SYNC-HAZARD-WRITE-AFTER-WRITE ] | MessageID = 0x5c0ec5d6 vkQueueSubmit(): WRITE_AFTER_WRITE hazard detected. vkCmdCopyBuffer...

Fix:
Added a per‑TransferTask fence to serialize transfer submissions so back‑to‑back vkCmdCopyBuffer writes can't overlap on the same queue.

OS Windows 11
GPU NVIDIA RTX 2000 Ada Generation Laptop GPU
Driver date 10/12/2025
Vulkan 1.4.328.1

[robertosfield]

I have merged this PR as a branch:

https://github.com/vsg-dev/VulkanSceneGraph/tree/TP-David-vkCmdCopyBuffer-sync-error-fix

I then compared master vs this branch running vsgviewer for 10 frames with the sync on:

vsgviewer models/openstreetmap.vsgt --sync -d -f 10 | grep Error

But alas the same errors for master and this branch :-|

vkQueueSubmit(queue, submitCount, pSubmits, fence) returns VkResultValidation Error: [ SYNC-HAZARD-WRITE-RACING-READ ] | MessageID = pointer
vkQueueSubmit(queue, submitCount, pSubmits, fence) returns VkResultValidation Error: [ SYNC-HAZARD-WRITE-RACING-READ ] | MessageID = pointer
vkQueueSubmit(queue, submitCount, pSubmits, fence) returns VkResultValidation Error: [ SYNC-HAZARD-WRITE-AFTER-READ ] | MessageID = pointer
vkQueueSubmit(queue, submitCount, pSubmits, fence) returns VkResultValidation Error: [ SYNC-HAZARD-WRITE-AFTER-READ ] | MessageID = pointer
vkQueueSubmit(queue, submitCount, pSubmits, fence) returns VkResultValidation Error: [ SYNC-HAZARD-WRITE-AFTER-READ ] | MessageID = pointer

Not yet sure of what to make of this.