Move maintained Tera evaluations to private source

docs/PRIME_FIRST.md

@@ -12,7 +12,9 @@ harness, trainer, runtime marketplace, or environment hub.
   explicit training handoff and artifact rendering.
 
 Lumbridge's unique work is the environment: task distributions, interactive
-state, rewards, probes, held-out gates, Tera bridges, and result interpretation.
+state, rewards, probes, held-out gates, and result interpretation. Tera bridges
+are developed with Tera because they package proprietary simulator source; they
+use the same upstream Verifiers contract without living in this public repo.
 Generic rollout and training machinery stays upstream. A Hub publication must
 exclude secrets, private task splits, customer data, and proprietary Tera source.
 

docs/TERA_BOUNDARY.md

@@ -0,0 +1,21 @@
+# Tera source boundary
+
+Arena is public Apache-2.0 environment work. Tera is Lumbridge's proprietary
+world simulator and is developed in the private `lumbridge-private/tera`
+repository.
+
+The `tera_spatial` bridge and `tera-crow-nav` taskset were previously committed
+to Arena. Those historical revisions remain available under the license granted
+when they were published; deleting current files does not revoke that grant or
+rewrite git history. As of 2026-08-25, maintained bridge code, vendored simulator
+closures, Tera tasksets, and new Tera releases live only with private Tera.
+
+The boundary is about source ownership, not rebuilding upstream machinery:
+
+- Arena and private Tera both depend on Prime Intellect Verifiers for the
+  environment/harness contract.
+- Forge delegates training to Prime-RL across a subprocess boundary.
+- No Lumbridge repository should implement its own generic rollout harness,
+  trainer, environment hub, or GPU marketplace.
+- Publishing an Arena environment to Prime Hub is a separate owner-approved
+  action. Nothing in this repository publishes automatically.