- Remove unconditional VK_KHR_swapchain request; offscreen renderer needs
no device extensions, fixing failures on headless/CI setups.
- Enumerate physical devices properly and pick the first one with a
graphics queue family instead of blindly choosing device 0.
- Check vkEnumeratePhysicalDevices/vkBindImageMemory/vkBindBufferMemory
results.
- Validate FindMemoryType() result before allocation and log clear errors.
- Add a persistent linear sampler created in PostInit and destroy it in
DestroyInternal.
- Fix DestroyInternal() early-return leak: now tears down the instance
even if device creation failed.
ctest passes 4/4.
Mike-Solar
f1d19a03f8