Function is_decoder_unavailable 

pub fn is_decoder_unavailable(err: &str) -> bool

2026-09-26: Does this error read as “the server cannot decode that container”? Such a leg is skipped, not failed: ffmpeg decoding is a deployment choice (--video-allow-ffmpeg).

The strings match the server’s messages in model-layers/src/video_decode_ffmpeg.rs (decode_frames, spawn_failure, the availability probe). That file’s tests pin only the “is ffmpeg installed” hint, so rewording the others there would turn these skips into failures without failing a test.