The Autoresearch Loop workflow (phase-a-toy) runs train.py, which reads
data/processed/eurusd_daily.parquet. data/ is gitignored (DVC/MinIO policy, #10),
but CI checks out a fresh tree with no data, so the baseline run died with
FileNotFoundError. Force-add this single 59KB derived fixture (public EUR/USD
daily realized vol, 2019-2023, 1560 rows) so the toy loop is hermetic and fast.
This is a scoped exception to #10 for a CI fixture only — large/production
datasets still stay out of git per that policy.
