Finish rail-kubernetes bootstrap handoff

docs/wave-1-contract.md

@@ -54,6 +54,13 @@ Wave 1 `rail-kubernetes` must not assume:
 Until the extraction is complete, `railiance-cluster` remains the compatibility
 surface for current operators.
 
-`rail-kubernetes` should become the durable home of the contract first. Only
-then should commands, docs, schemas, and helpers move here in a migration-safe
-sequence.
+The current migration-window handoff is:
+
+- `rail-kubernetes/bin/railiance` is the canonical owner for the six generic
+  lifecycle commands;
+- `railiance-cluster/bin/railiance` keeps those command names as a thin
+  delegation shim with a temporary local fallback;
+- retained S2 operations and non-rail helper debt stay outside this handoff.
+
+See `docs/cluster-compatibility-handoff.md` for the command-resolution path and
+operator migration steps.