Add .gitattributes so *.mp4/*.mov/*.webm are stored via Git LFS, and
commit the 8 social-media ad clips (ad-01…ad-08) shown on the new
Learn → Videos subpage. The .mp4 files are stored as LFS pointers; the
.jpg poster frames remain normal blobs (force-added past the global
*.mp4/*.jpg ignore rules).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
