diff --git a/docs/roadmap/implementation.md b/docs/roadmap/implementation.md
index c344db1..bc2a4a2 100644
--- a/docs/roadmap/implementation.md
+++ b/docs/roadmap/implementation.md
@@ -199,6 +199,11 @@ Push the validated commit and record its full ID as PIPELINE_ROLE.
 
 ## Stage 4: Assemble the Public Collection Snapshot
 
+Completion: complete — subtree import `b6d7130` and final collection commit
+`ce5b838d95050f7e6c0fde4d483d269daf5d6e0a` are published on `origin/main`;
+`tests/integration`, subtree tree-identity comparison, `bash -n tests/integration`,
+and `git diff --check` passed.
+
 ### Required Policy Review
 
 Read `AGENTS.md`, `docs/orientation.md`, `docs/conventions.md`,