Verify scoped collection behavior and complete roadmap

docs/roadmap/implementation.md

@@ -1,6 +1,7 @@
 # Configuration Collections Implementation Plan
 
-Status: ready for implementation; no feature changes are implemented by this plan.
+Status: implementation complete; roadmap retirement remains for normal release
+preparation.
 
 Implement the accepted [feature roadmap](configuration-collections.md). That
 document owns intent, scope, and selected policy; this document owns API delivery
@@ -828,6 +829,20 @@ Scope: focused integration gaps and final regression validation, not new feature
    release preparation. Do not publish, wait for CI, probe providers, or introduce
    a catalog-release dependency to finish implementation.
 
+Completion: acceptance coverage was traced across public collection assembly,
+scoped execution and inspection, full-ID listings and inventories, exact stored
+defaults, optional prompt labels, prepared selection capture, source headers and
+origins, final-value validation, namespaced redaction, and retained effective
+configuration shape. Added a controlled concurrent regression test proving an
+ordinary call and a differently scoped call share one collection backend's
+capacity. Audited current source, tests, and docs for obsolete selectors,
+automatic catalogs, built-in profile promises, and local module replacements;
+remaining version references are descriptive labels or migration guidance.
+Marked the feature roadmap complete; normal release preparation owns retirement.
+Validation passed: `GOWORK=off go test -race ./...`, `GOWORK=off go vet ./...`,
+`GOWORK=off python3 scripts/check-examples.py`, `gofmt`, local Markdown link
+checks, and `git diff --check`.
+
 ## Open Questions
 
 None required to begin implementation. The feature roadmap's policy decisions