Distill principles batch 01: 2020-08 through 2022-10 (20 recordings)
Newest-first stage-4 backfill begins: 8 streams and 12 videos, 161
bullets, registered in principles_files with exact transcript
provenance. Also: register_principles.py gains per-file selection for
batch workflows, and the one formerly-stale distillation (smD91VwGVSY)
was re-verified against its butler transcript and repointed.
