Fix CUDA option not appearing on Linux due to preprocessor macro typo

[Copilot]

On Linux systems with CUDA-enabled ONNX Runtime, the CUDA inference option was missing from the UI despite successful build-time detection.

Root Cause

Preprocessor macro typo in background-filter.cpp:

• Used: HAVE_ONNXRUNTIME_CUDA_CP
• Expected: HAVE_ONNXRUNTIME_CUDA_EP

CMakeLists.txt defines HAVE_ONNXRUNTIME_CUDA_EP when CUDA support is detected. The typo caused the conditional compilation block to never execute, preventing the CUDA option from being added to the UI dropdown.

Changes

• Fixed macro name to match CMake definition and align with other execution providers (ROCM_EP, TENSORRT_EP)
• Consistent with correct usage in enhance-filter.cpp

// Before
#ifdef HAVE_ONNXRUNTIME_CUDA_CP
    obs_property_list_add_string(p_use_gpu, obs_module_text("GPUCUDA"), USEGPU_CUDA);
#endif

// After  
#ifdef HAVE_ONNXRUNTIME_CUDA_EP
    obs_property_list_add_string(p_use_gpu, obs_module_text("GPUCUDA"), USEGPU_CUDA);
#endif

Original prompt

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This section details on the original issue you should resolve

<issue_title>CUDA option not available on Linux</issue_title>
<issue_description>### Operating System

Arch Linux

Other OS (if not listed above)

No response

Plugin Version

1.3.3

OBS Studio Version

32.0.1

OBS Studio Log URL

https://obsproject.com/logs/OJ8FxWPEJpaTuF9Z

OBS Studio Crash Log URL (if applicable)

No response

Expected Behavior

The option should be present.
From build logs:

-- Looking for OrtSessionOptionsAppendExecutionProvider_CUDA in onnxruntime::onnxruntime
-- Looking for OrtSessionOptionsAppendExecutionProvider_CUDA in onnxruntime::onnxruntime - found
-- ONNX Runtime CUDA Execution Provider found

Actual Behavior

No option other than CPU.

Steps to Reproduce

1. Compile the AUR package with onnxruntime-cuda installed
2. Add filter to webcam source
3. Notice no option for using the GPU

Additional Notes / Screenshots

There is a typo here:

obs-backgroundremoval/src/background-filter.cpp

Line 160 in 1ce5693

#ifdef HAVE_ONNXRUNTIME_CUDA_CP

it should end in _EP

Confirmation

• I have attached the required OBS log file(s).</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes CUDA option not available on Linux #712

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[umireon]

@royshil review plz

[royshil]

Great!