* Add holdout-labs research-integrity family; fix falsification-ledger org link
- fix stale foolproof-labs link on falsification-ledger (org migrated to holdout-labs; PR #593 entry)
- add pit-adjuster and ashare-data-immunity (Market Data & Data Sources)
- add factor-qc and lookahead-free (Factor Analysis)
- add lesson-book (Trading & Backtesting)
All Python, MIT, zero/standard deps, tested; sibling of the accepted falsification-ledger.
* Drop falsification-ledger org-link hunk from this PR (tracked separately in #611)