Record shallow directory selection completion

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Implementation Plan: Import Discovery and Dependency-Ready Ordering
 
-Status: Stages 1–9 complete; 10 implementation stages remain.
+Status: Stages 1–10 complete; 9 implementation stages remain.
 
 ## Authority, baseline, and execution
 
@@ -438,6 +438,12 @@ missing root alongside one that supplies the required match.
 Acceptance: shallow directory tests pass with actual host files and a native
 filesystem; no per-root/per-pattern requiredness is introduced.
 
+Completion: implemented in commit `55a59de` (`Select shallow directory import
+sources`). Verified with shallow-selection tests on host and native filesystems,
+the full engine suite, a focused race run, `go vet ./...`, `go build ./...`, and
+`git diff --check`. The everyday check still reaches only the consumer
+sequence-order expectations reserved for Stage 18. Stage 11 onward remains.
+
 ## Stage 11 — Add recursive directory traversal and depth accounting
 
 Extend the walker with explicit traversal frames, effective recursion, and the