Finish rail-kubernetes bootstrap handoff

workplans/RAIL-K8S-WP-0001-bootstrap-and-wave1-import.md

@@ -4,7 +4,7 @@ type: workplan
 title: "Bootstrap rail-kubernetes and import the wave-1 contract"
 domain: financials
 repo: rail-kubernetes
-status: active
+status: finished
 owner: codex
 topic_slug: railiance
 created: "2026-07-25"
@@ -99,7 +99,7 @@ verified the imported surface with `bash -n`, `python3 -m py_compile`, and
 
 ```task
 id: RAIL-K8S-WP-0001-T03
-status: wait
+status: done
 priority: medium
 state_hub_task_id: "18140d90-d10e-47fe-b7da-d454550466b1"
 ```
@@ -113,6 +113,14 @@ Acceptance:
 - current operators do not need a flag day
 - the retained S2 surface stays narrow and temporary
 
+2026-07-26: Added `docs/cluster-compatibility-handoff.md` as the canonical
+handoff contract for the migration window. On the cluster side,
+`railiance-cluster/bin/railiance` now delegates `create-overlay`, `run`,
+`deploy`, `observe`, `promote`, and `rollback` to `rail-kubernetes` when a
+configured or sibling checkout exists, with a temporary local fallback when it
+does not. This keeps current operator entrypoints working without expanding the
+rail boundary.
+
 ## T04 - Register `rail-kubernetes` in State Hub and Fabric
 
 ```task