ci: exempt images and notebooks from 100 KB file-size gate

Documentation assets (PNG/JPG/GIF/SVG/ICO/WebP) and Jupyter notebooks
(.ipynb) are legitimate large files that should not be blocked by the
binary-size check. Notebooks can embed base64-encoded images to ensure
self-contained rendering on GitHub.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ivanbasov