Replay recording produces an empty file when AI tracking is active

[mohamedtahaguelzim]

With AI tracking (which engages the lookahead buffer), the GPU atlas recorder attaches but never receives frames: log ends with GpuAtlasRecorder: finished (0 atlases recorded, 0 failed) and the .mkv is ~550 bytes. Non-tracked exports record correctly (88/88 atlases on the same input). Repro: --model yolo.onnx --allow-no-tracking --lookahead 1.5 --replay r.mkv. Reproduced on both the 0.5 line and dev: the lookahead render path lacks the atlas-recording hook. CPU-resident sources are unaffected (ReplayRecordingSource decorator path works).

[mohamedtahaguelzim]

the empty file is caused by the lookahead buffer, not AI itself (AI enables lookahead by default). The buffered render path never feeds the replay recorder.