Record deterministic scheduler completion

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Implementation Plan: Import Discovery and Dependency-Ready Ordering
 
-Status: planned; no implementation stages completed.
+Status: Stage 1 complete; 18 implementation stages remain.
 
 ## Authority, baseline, and execution
 
@@ -230,6 +230,11 @@ assert equal schedules/cycles. Do not assert heap internals.
 
 Acceptance: focused scheduler tests pass; no loading behavior changes.
 
+Completion: implemented in commit `167fcd4` (`Add deterministic dependency
+scheduler`). Verified with `go test ./internal/engine -run
+'^TestScheduleDependencies' -count=1`, `./scripts/check.sh`, and
+`git diff --check`. Loading behavior remains unchanged; Stage 2 onward remains.
+
 ## Stage 2 — Separate inheritance graph analysis from application
 
 In `inheritance.go`, extract direct-sibling relationship analysis from the