Prepare bounded speech diagnostics and document mixed routing risks

docs/SPEECH-ALIGNMENT.md

@@ -4,6 +4,11 @@ Status: researched implementation proposal, 2026-10-13. No transcription worker,
 download integration, or ASR quality result is implemented by this document.
 Google EmbeddingGemma 2 remains the production semantic model.
 
+A bounded [CPU diagnostic harness](../tools/speech-eval/README.md) is now prepared.
+Seven structural tests passed on Windows, including actual owned subprocess
+failure, timeout, output overflow and retained diagnostics. No ASR model has been
+downloaded or run for this proof; these tests establish no speech quality.
+
 ## Why add a transcript lane
 
 [The frozen media evaluation](MEDIA-QUALITY.md) found the correct spoken-topic