fix(windows): request compute-capable WGPU limits

[daylight-00]

Summary

Initialize Patinae's native WGPU settings with wgpu::Limits::default() before applying the renderer-specific storage-buffer count.

Slint's WGPUSettings::default() uses WebGL2-compatible downlevel limits. On the Windows automatic WGPU path this leaves compute and storage limits at zero, so Patinae successfully acquires the GPU and loads structures but cannot create its compute pipelines or scene-store bindings.

This change:

• replaces the zeroed WebGL2/downlevel device limits with normal WebGPU defaults for the native renderer;
• preserves Patinae's existing max_storage_buffers_per_shader_stage override;
• adds a regression test ensuring the settings expose non-zero compute/storage capability.

Reproduction

Observed on Windows with Intel HD Graphics 530 / DX12 after #28.

Before:

wgpu device limits: max_storage_buffer_binding_size=0 ... max_compute_workgroups_per_dimension=0
...
Shader entry point's workgroup size [64, 1, 1] ... limit ... [0, 0, 0]
...
Buffer binding ... exceeds `max_*_buffer_binding_size` limit 0

After the change:

wgpu Windows configuration: backends=Backends(DX12) requested max_storage_buffer_binding_size=134217728 max_buffer_size=268435456 max_storage_buffers_per_shader_stage=10
wgpu device limits: max_storage_buffer_binding_size=134217728 max_buffer_size=268435456 max_compute_workgroups_per_dimension=65535 max_texture_dimension_2d=16384
GPU: Intel(R) HD Graphics 530 (Dx12)

The same structure then renders successfully on that machine.

Notes

The non-Windows path already replaces Slint's settings with adapter-derived limits before request_device; the Windows automatic path relies directly on WGPUSettings, which is why the zeroed defaults surfaced there.

[Copilot]

🟢 Approval recommended

The change is narrowly scoped to WGPU settings initialization and is backed by a focused regression test covering the reported failure mode.

Pull request overview

This PR fixes Windows native WGPU initialization by replacing Slint’s WebGL2/downlevel default limits (which can zero out compute/storage capabilities) with wgpu::Limits::default() before applying Patinae’s storage-buffer-stage override, and adds a regression test to ensure the requested limits remain compute-capable.

Changes:

• Set settings.device_required_limits = wgpu::Limits::default() in patinae_wgpu_settings() so Windows “Automatic” WGPU config requests compute/storage-capable limits.
• Preserve the existing max_storage_buffers_per_shader_stage override.
• Add a regression test asserting non-zero compute/storage-related limits in the settings.

File summaries

File	Description
patinae/src/app.rs	Requests WebGPU-default device limits to avoid zeroed compute/storage limits on Windows automatic WGPU path; adds a regression test for compute/storage capability.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Lite

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[Copilot]

🟡 Changes recommended

The new regression test doesn’t assert the specific compute workgroup-size limit that triggered the reported failure, so it may not reliably catch the original bug.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 2
• Review effort level: Lite

[Copilot]

🟢 Approval recommended

The change is small, directly addresses the reported Windows failure mode, and includes a focused regression test for the requested limits.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0 new
• Review effort level: Lite