Run 2026-10-01 with 82 s of synthetic Swedish muxed with black video (H.264 + AAC .mp4, built with the real ffmpeg): accepted, had_video=true, transcribed by iguana/kb-whisper, the page said only its audio was used, and chat answered. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>