Add ergonomic Vulkan device API

[antono3]

Summary

• discover queue families and select the first family containing every required QueueFlags bit
• create a logical device with one priority-1.0 queue, load Volk device commands, and expose raw Device and Queue handles
• document explicit device/queue lifetime rules and add pure queue-selection tests

Verification

• v fmt -verify ergonomic/ergonomic.v ergonomic/ergonomic_test.v
• v -check-syntax ergonomic/ergonomic.v
• v -check-syntax ergonomic/ergonomic_test.v
• git diff --check

Full binding compilation is delegated to GitHub Actions per repository guidance.