m3ultra e31e8ac559 Festival 4D build spec + parallel lane plan for Opus agents

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

2026-07-16 00:06:54 +10:00

Lane A — Media pipeline (branch `lane/a-media`)

Scope: spec milestone M1 (ingest + GCC-PHAT audio sync + pairwise graph solve + drift estimation).

Owned files: backend/festival4d/ingest.py, backend/festival4d/audio_sync.py, backend/tests/test_ingest.py, backend/tests/test_audio_sync.py. Nothing else.
Fill the stub bodies foundation left; do not change their signatures (CLI and API already call them).
Verify against the synthetic fixture: python -m festival4d ingest && python -m festival4d sync must recover the ground-truth offsets recorded by synthetic.py (spec M1 tolerances: ±10 ms offsets, ±3 ppm drift).
Write results through db.py helpers only; also export data/work/sync.json as spec'd.
Respect spec pitfall #5: disconnected sync-graph components → offset_ms=NULL, never a guess.

Done when: spec M1 acceptance passes, pytest green, merged to main with synthetic end-to-end intact.

Lane A — Media pipeline (branch lane/a-media)