Resolve conflicts with #4's "Auto on Windows leaves Vulkan out when an
Intel adapter is present" (3c9c93ed) and #7813's adapter choice
(`configure` gained `wanted`):
- gpu_startup.rs: `intel_dx12_applied(.., vulkan_left_out)` from main and
the patch's `dx12_default_applied` become one
`dx12_default_applied(adapters, chosen, os, vulkan_left_out)` that
returns the maker's name (Intel or Qualcomm). `vulkan_left_out` counts
only for Intel, since only an Intel DXGI adapter makes
`windows_auto_backends` drop Vulkan. `configure` keeps main's `wanted`
parameter and Vulkan-free instance; the System Info note names the maker.
- Tests: keep both main's Intel instance test and the Qualcomm test,
updated to the merged signature, plus one assertion that Vulkan being
left out doesn't make a Qualcomm DX12 pick "the default".
- Module docs and docs/development.md: main's wording, with Qualcomm
(Windows on ARM) added to the DX12 default.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
