The playback pipeline already typefinds by content and decodes GIFs
via GStreamer's decodebin like any other video, but the preferences
file picker filtered to video/* MIME types only, hiding .gif files.
Widen the filter to include image/gif and *.gif, add an "All files"
fallback, and update the related copy/docs to mention GIF support.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019RDqbdjsiisSU7CbQke4g8