Pre-flight checklist

• I have read/searched the documentation
• I have searched existing issues to avoid duplicates

Bug Description

SISR crashes during startup on my Windows machine when an older Vulkan SDK DXC/DXIL pair is visible on PATH.

This was reproduced and investigated with help from Codex as I know nothing about Rust. Apologies for AI slop in advance. The issue appears related to wgpu's DX12 shader compiler selection. With my normal PATH, SISR loads dxcompiler.dll / dxil.dll from Vulkan SDK and exits with a Rust panic. If I remove only the Vulkan SDK Bin directory from PATH for the SISR process, SISR starts successfully and loads d3dcompiler_47.dll instead.

To Reproduce

Exact steps to reproduce the behavior:

1. Install/run SISR on Windows.

2. Have this directory on PATH:

   C:\VulkanSDK\1.3.224.1\Bin
   

   This is from VulkanSDK-1.3.224.1-Installer.exe.

3. Confirm that directory contains these files:

   C:\VulkanSDK\1.3.224.1\Bin\dxcompiler.dll
     FileVersion: 1.7.0.3618
   
   C:\VulkanSDK\1.3.224.1\Bin\dxil.dll
     FileVersion: 101.6.2112.13
   

4. Start SISR normally, or run a minimal startup test:

   C:\Users\bruce\AppData\Local\SISR\SISR.exe `
     --console true `
     --tray false `
     --no-steam true `
     --update-notify none `
     --window-create true `
     --window-fullscreen false `
     --log-level debug

5. SISR exits during graphics initialization with exit code 101.

6. As a workaround test, run SISR with only the Vulkan SDK directory removed from PATH for that process:

   $env:Path = (($env:Path -split ';') |
     Where-Object { $_ -ne 'C:\VulkanSDK\1.3.224.1\Bin' }) -join ';'
   
   & "$env:LOCALAPPDATA\SISR\SISR.exe" `
     --console true `
     --tray false `
     --no-steam true `
     --update-notify none `
     --window-create true `
     --window-fullscreen false `
     --log-level debug

7. With that workaround, SISR starts successfully.

Expected Behavior

SISR should start normally.

If DX12/wgpu initialization fails, SISR should report an actionable error instead of crashing during startup.

Actual Behavior

With the Vulkan SDK DXC/DXIL pair visible on PATH, SISR exits with code 101.

Observed panic:

Failed to create device: RequestDeviceError { inner: Core(Device(Lost)) }

In a diagnostic run after getting past device creation, the later failure was:

wgpu error: Validation Error

Caused by:
  In Device::create_render_pipeline, label = 'egui_pipeline'
    Internal error in ShaderStages(FRAGMENT) shader:
    DXC compile error: error: validator version 1,6 does not support target profile.

Screenshots/Logs

Attached raw logs:

• SISR.log from %APPDATA%\SISR\data\SISR.log
• SISR-panic-stderr.txt captured from stderr while reproducing the crash

Relevant diagnostic findings with normal PATH:

WGPU_BACKEND=None
WGPU_DX12_COMPILER=None

DX shader compiler candidate:
C:\VulkanSDK\1.3.224.1\Bin\dxcompiler.dll

DX shader compiler candidate:
C:\VulkanSDK\1.3.224.1\Bin\dxil.dll

Selected adapter:
NVIDIA RTX PRO 6000 Blackwell Workstation Edition
backend=Dx12
driver="32.0.15.9597"

Failed to create device:
RequestDeviceError { inner: Core(Device(Lost)) }

Loaded modules in the failing case:

C:\VulkanSDK\1.3.224.1\Bin\dxcompiler.dll
C:\VulkanSDK\1.3.224.1\Bin\dxil.dll

Loaded modules in the working workaround case:

C:\WINDOWS\SYSTEM32\d3dcompiler_47.dll
  FileVersion: 10.0.26100.8328

In the working workaround case, dxcompiler.dll and dxil.dll were not loaded.

Environment

• OS: Windows
• GPU: NVIDIA RTX PRO 6000 Blackwell Workstation Edition
• NVIDIA Driver: 595.97
• SISR Version: 0.3.1
• VIIPER Version: 0.6.0
• USB-IP Version: 0.9.7.7
• Vulkan SDK on PATH: C:\VulkanSDK\1.3.224.1\Bin

Additional Context

This may be environment-sensitive rather than purely a SISR logic bug, but it is brittle for an installed application because startup depends on whichever dxcompiler.dll / dxil.dll pair appears first in DLL search / PATH.

It is possible that installing a newer Vulkan SDK would make this specific reproduction go away, but I have not tested that because I currently have another project relying on this SDK version.

Codex's Suggestions:

• In the main executable, handle DX12/wgpu initialization errors more gracefully and include actionable logging.
• Log which DX shader compiler DLLs are visible or loaded when DX12 initialization fails.
• If FXC is acceptable for SISR, consider selecting it explicitly in code instead of leaving wgpu's DX12 compiler selection on Auto, for example by setting Dx12BackendOptions { shader_compiler: wgpu::Dx12Compiler::Fxc, ... }.
• Consider documenting WGPU_DX12_COMPILER=fxc as a user workaround.
• If DXC is preferred, consider shipping a known-good matched dxcompiler.dll / dxil.dll next to SISR.exe.
• The installer script could detect known problematic DXC/DXIL pairs on PATH and warn the user.