Document smoke-test diagnostics

docs/roadmap/implementation.md

@@ -1,6 +1,6 @@
 # Smoke Test Diagnostics Implementation Plan
 
-Status: ready for implementation.
+Status: implementation in progress; integrated candidate validation remains.
 
 Implement the accepted [feature roadmap](smoke-tests.md). This document owns the
 implementation sequence; the feature roadmap owns the requested API, factual
@@ -711,6 +711,18 @@ Validate: local documentation paths/anchors, GoDoc against implemented behavior,
 and any changed example snippets through focused offline tests. No online link
 availability or human sign-off gate.
 
+**Completed: 2026-10-13.** Updated the consumer guide, backend format reference,
+OpenAI-compatible integration contract, internal component inventory and
+diagnostic mechanics, and README navigation. The later release note should
+describe the explicit live `Engine.SmokeTest` API and its operational boundary;
+the selected catalog candidates `v3.20261013.0` remain local and unpublished
+(OpenRouter `2a69672b1bb220f1a730153341470f5ac67e15f4`, Rakestrawhome
+`d40a8aad50111c15d279469170f7b5032ac22529`). Publication-date re-pinning may be
+needed before a distributable PromptKit release. No release note was rewritten
+and no catalog or PromptKit publication was attempted. Validation passed:
+local Markdown paths/anchors, public GoDoc review, `go test . -run Smoke`,
+`go test ./internal/usecase -run Smoke`, and `git diff --check`.
+
 ## Stage 19: Validate The Integrated Candidate And Record Handoff
 
 Scope: final verification, completion records, and unintended-file cleanup.