Document host-native release launchers

docs/roadmap/implementation.md

@@ -160,6 +160,8 @@ checks in Stage 6.
 
 ## Stage 6: Align consumer guidance and verify the sprint
 
+**Completed.**
+
 1. In the [adoption guide](../consumers/adoption.md), make the minimal
    launcher use the Stage 1 recipe followed by `exec go tool releasekit "$@"`.
    Run it from the selected module, retaining that consumer's workspace and