Bundle data files correctly with PyInstaller (and avoid broken paths)

The problem

Hard-coded relative paths often break after packaging. Onefile also extracts files to a temp directory, so your runtime path changes.

The clean pattern

• Include assets using PyInstaller’s data-file options.
• Resolve the runtime base directory in code and build paths from it.

What to bundle

• UI assets (icons, images)
• Config templates
• ML models
• Default data files

Tip: In PyInstaller GUI, keep assets grouped and add them as a folder to avoid missing individual files later.