- Add pipeline_events table (migration 004) for structured stage logging
- Add PipelineEvent model with token usage tracking
- Admin pipeline dashboard with video list, event log, worker status,
trigger/revoke controls, and collapsible JSON payload viewer
- Version switcher on technique pages — view historical snapshots
with pipeline metadata (model names, prompt hashes)
- Frontend types for pipeline admin and version APIs
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
