Added
- `next/` `.zt` animation decoder (Phase A5): `next/services/media.py` gains a `ZtDecoder` class that reads Thermalright's `Theme.zt` JPEG-sequence archives (the format `UCVideoCut.BmpToThemeFile` writes). Parses 0xDC magic, frame_count, per-frame absolute timestamps, and back-to-back JPEG payloads; one `ffmpeg jpeg_pipe` per frame scales to requested size; fps derived from average inter-frame delay.
- `MediaService.load_video` now dispatches by suffix — `.zt` → `ZtDecoder`, `.mp4`/`.mov`/`.webm`/etc → `VideoDecoder`.
- Synthetic round-trip verified: 2-frame red/blue archive decodes to correct pixels at correct fps (10 from 100ms delay).
- Pure Python; no legacy or shipping behaviour changed; gap filled only in the experimental `TRCC_NEXT=1` build.