Verify Linux (Ubuntu) build actually runs, not just compiles

[dcwhite]

Summary

The Linux build currently compiles successfully on Ubuntu, but we haven't confirmed that the resulting binary actually launches and runs correctly. Need to verify runtime behavior, not just build success.

Tasks

• Build SCIRun on a clean Ubuntu install (specify version, e.g. 22.04/24.04) following build.sh instructions
• Launch the built scirun binary (both GUI and -DBUILD_HEADLESS=ON variants)
• Confirm the main window opens without crashing (GUI build)
• Load and execute a basic sample network (.srn5) end to end
• Check for missing shared library / runtime dependency errors
• Note any Qt, OpenGL, or other runtime issues specific to Ubuntu

Notes

Build passes on CI/locally, but no one has confirmed the app runs post-build on Ubuntu. This issue is to close that gap.