2.1.2

Fixed

• matroska: TrackTimestampScale != 1.0 is now clamped to 1.0 with a warning (patch_ffmpeg_matroska_tts). Upstream FFmpeg (n8.1.2 and current master) bakes the track's TrackTimestampScale into the stream time base but divides only the cluster component of each block timestamp by it, so packets landed on a silently wrong hybrid axis (cluster + rel x scale): neither the unscaled nor the fully scaled axis, non-monotonic in storage order, with packet durations off by a factor of the scale. The element is deprecated (RFC 9559 caps it at Matroska v3) and matroska.org documents that most readers ignore it, so a real-world non-1.0 value is almost always muxer damage; full spec scaling would desync the track from its siblings. Clamping keeps every track on the coherent segment axis, and the deviation is logged instead of silent. Fixes AetherEngine issue #145.

No other changes; FFmpeg stays at n8.1.2, dav1d 1.5.1, zimg 3.0.5, zvbi 0.2.44.