## What
Follow-up to v0.2.3. Three related fixes:
1. **Complete the phrase-frequency report.** The v0.2.3 CHANGELOG states the report was recomputed, but the README carried a "recount pending" note and the committed snippet was a stale 15-source run (missing `nkjp1m`). Regenerated across all 16 sources with `src/pattern_frequency_report.py`: total **6,881,277,362** tokens, refreshed tables + 10 charts, and replaced the pending note in the README "Results" section.
2. **Fix SOURCES registry drift.** `1000_novels` and `global_voices` shipped in `data/` but were unregistered in `src/sources.py`, so `make_docs.py` silently dropped them (saw 14/16 sources, wrong totals) and would regress the README on the next run. Registered both, with a new `custom_datasheet` guard in `make_docs.py` so their hand-authored datasheets and per-source "Added" dates are not clobbered by template regeneration.
3. **Add AGENTS.md.** Documents the add-source and release ritual plus the real footguns (make_doc…
Clarify stable releases versus validation artifacts
