LearnSpark real-fire loop and poster

Adapted from "Fire burning.ogv" by Zouavman Le Zouave.
Source: https://commons.wikimedia.org/wiki/File:Fire_burning.ogv
Original footage recorded 26 December 2007 in Ranua, Finland.

Original and adapted flame-loop.mp4 / flame-poster.webp licensed under
Creative Commons Attribution-ShareAlike 4.0 International:
https://creativecommons.org/licenses/by-sa/4.0/

Changes by LearnSpark: cropped to flames, resized, softened crop boundaries,
removed audio and metadata, crossfaded into a loop, compressed, and extracted
a still poster. These derived media assets remain under CC BY-SA 4.0.

Rebuild: python scripts/build-fire-footage.py PATH_TO_Fire_burning.ogv