Unify analysis pipeline around the TSV; move tracked DBs out of cloud sync

- Tracked DBs now live at /mnt/data/projects/cupido/tracked/ (out of
  ownCloud to avoid sync conflicts and bandwidth churn). config.py
  TRACKING_OUTPUT_DIR points there; the docker-compose for ethoscope-lab
  mounts it world-readable for JupyterHub users.
- New scripts/export_video_db_index.py joins all_video_info_merged.xlsx
  with the video inventory and the on-disk DBs, producing a TSV that has
  one row per fly/ROI plus training/testing video and DB paths. Handles
  approximate xlsx times, cross-day training/testing, the 12 AM/PM
  ambiguity, and date typos.
- scripts/load_roi_data.py rewritten as a TSV-driven loader returning a
  single DataFrame with session and metadata columns. calculate_distances
  and the two flies_analysis notebooks migrated to use it; downstream
  trained/naive splits remain available via simple equality filters.
- Metadata vocabulary canonicalized: {naïve, niave, untrained, test} all
  resolve to {trained, naive}. Normalization happens at the TSV-export
  boundary (idempotent); the xlsx and the 2025-07-15 legacy CSV were
  edited in place to remove the worst variants.
- scripts/monitor_tracking.py rate calculation fixed: with N parallel
  workers, completions arrive in bursts; the old formula divided by burst
  width and reported nonsense rates. Now uses a 6 h window denominator.
- scripts/track_videos.py: BGRMovieCamera retries cv2.read on transient
  NFS hiccups and a post-tracking completeness gate (≥ 90 % of expected
  duration via MAX(t) across all 6 ROIs) deletes silent partial DBs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -66,7 +66,7 @@ python scripts/pick_targets.py --redo      # re-pick already-picked videos
 
 # 3) batch tracking (idempotent, can run in background)
 python scripts/track_videos.py --jobs 4    # parallel
-# output → data/tracked/*_tracking.db (SQLite, same schema as data/raw/)
+# output → /mnt/data/projects/cupido/tracked/*_tracking.db (SQLite, same schema as data/raw/)
 ```
 
 See `tasks/todo.md` "Offline Tracking" section for the full plan, and