Test the preparation example in Go

docs/roadmap/implementation.md

@@ -123,6 +123,11 @@ Validation: format and run `go test ./examples/go-library/prepare`. Ensure
 imports and relative content still resolve from their contributing sources;
 do not rewrite configuration fixtures merely to bypass path handling.
 
+Completion: the preparation workflow accepts an explicit context, example
+directory, and writer while preserving its inline checks and source contexts.
+Its Go test verifies the retained summary, including explicit null collection
+metadata, and passed on Go 1.27.0.
+
 ## Stage 3: Test The Observation Example And Its Output
 
 Scope: `examples/go-library/observe/main.go` and its new `main_test.go`.