The sidecar was crashing (exitCode: null) when invoked from Tauri
because Windows couldn't locate onnxruntime.dll in the sidecar directory.
Added setup_cmd() helper that:
- Adds the sidecar directory to the child process PATH
- Sets the child process CWD to the sidecar directory
This ensures Windows can find all required DLLs when Tauri invokes
the sidecar, matching the behavior of manual command-line execution.
Evandro
c9f0147c0d