Complete ReleaseKit adoption roadmap

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # ReleaseKit v0.9.0 implementation plan
 
-Status: Stages 1–5 complete; Stage 6 is not started.
+Status: Stages 1–6 complete.
 
 Implement these stages in integer order during one end-to-end sprint. The target
 audience is the Luna coding agent. Intermediate stages may temporarily leave
@@ -98,7 +98,8 @@ under the local commit policy.
 **Completed.** Go 1.26.8 selected and downloaded v0.9.0; tidy changed only
 the tool requirement and its two checksum entries. The helper reported
 `releasekit v0.9.0` under foreign target and workspace settings without changing
-module metadata. Documentation alignment and snapshot checks follow.
+module metadata. In accordance with the requested per-stage commits, metadata
+was committed separately before documentation alignment and snapshot checks.
 
 From the repository root, put Go 1.26.8 on `PATH` using the existing
 [toolchain setup](../release.md#release-toolchain). Use normal dependency
@@ -302,7 +303,11 @@ accurately. These results complement Stage 4; they do not authorize a release.
 
 ## Stage 6: Review completion evidence and finish the sprint
 
-**Status:** not started.
+**Completed.** The complete diff was reviewed against the feature roadmap.
+The only Go source change is the completion assertion; the scripts, profiles,
+integration modules, production APIs, and R1/R2 fixes remain unchanged. The
+root and workspace-backed integration checks cover the Stage 4 snapshot;
+subsequent changes only record completion and update roadmap status.
 
 1. Review the complete diff against the feature roadmap. Confirm the only code
    change is the order-independent test assertion; metadata selects v0.9.0;