[rgward]

Summary

• Add Joey D'Antonio to the quote-contributor credits on the first inner page of the book GIF and 4K MP4.
• Regenerate both media files and document the credit.

Validation

• GIF: all 270 frames decoded; 640 x 640; 68.80 seconds; 4,823,237 bytes (under 5 MB).
• MP4: full decode validation passed; 3840 x 2160 at 25 fps; 146.20 seconds.
• Visually confirmed the credit fits without clipping.
• Updated MP4 is included as a regular Git blob (25,545,929 bytes), not an LFS pointer.
• MP4 SHA-256: F210695C16C07C2F13116F4504D0A21195F930620D3980B895E3D3D56C73A35F.

The unrelated local ignore-file change is excluded.