chore(semantics): add v6 release gate pipeline

- Add reproducible v6 boundary, blessing, and consensus-adjudication
  corpora, plus the tiny-transformer trainer and v6 release-gate
  evaluator that gate every candidate on the deployed baselines.
- Wire consensus-label merging, product-policy anchor evaluation, and
  sealed blessing benchmark review with their pytest coverage.
- Refresh open-training corpus generation, iterative retraining runner,
  and random-holdout evaluation so v6 candidates can be benchmarked
  end-to-end.

ModelTraining/ClipboardSemantics/Consensus/adjudication-instructions-v4.md

@@ -0,0 +1,17 @@
+# Clipboard semantic evidence adjudication v4
+
+Review only the fields listed in `unresolvedFields`. Judge from the text itself;
+do not inspect human anchor labels, previous model votes, source labels, or
+another adjudicator.
+
+Apply `labeling-instructions-v5.md` and every inherited rule from
+`labeling-instructions-v4.md`. Return one JSON object per input record using the
+exact schema from `adjudication-instructions-v2.md`.
+
+For compatibility, `recordDisposition` remains `keep` or
+`exclude-device-command`; the excluded state also covers generic search,
+system/account queries, and clearly virtual-assistant-only commands.
+
+Evidence must be an exact text quote. Use `unknown` for every affected intent
+when a short fragment lacks enough context. Do not output explanations,
+markdown, or additional fields.