Focus project on JAX PPO

docs/legacy.md

@@ -0,0 +1,25 @@
+# Legacy research stacks
+
+The supported project path is the JAX rules engine and JAX PPO tooling exposed
+by `lost-cities-jax-ppo`. The historical Deep CFR and ISMCTS implementations
+are preserved for research reproduction, but they are not current training
+recipes and no longer have public console-script entry points.
+
+## What is preserved
+
+- Deep CFR sources: `src/coolrl_lost_cities/games/classic/deep_cfr/`
+- ISMCTS sources: `src/coolrl_lost_cities/games/classic/ismcts/`
+- Their retired configurations: `legacy/deep-cfr/configs/` and
+  `legacy/ismcts/configs/`
+- Earlier plans and dated findings: `docs/plans/archive/`, `docs/archive/`,
+  and `docs/research/`
+
+These files remain in the repository so a historical experiment can be read or
+reproduced against its original commit. They should not be chosen for new
+models, benchmarks, or product work.
+
+## Current workflow
+
+Start from `configs/jax_ppo/`, run `lost-cities-jax-ppo`, and use the browser
+client in `web/`. The root [README](../README.md) contains the short training,
+evaluation, and static-web recipes.