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/labeling-instructions-v3.md

@@ -0,0 +1,46 @@
+# Clipboard semantic consensus labeling v3
+
+Prompt version: `clipboard-consensus-v3`
+
+Label each record independently using only its text. Do not infer missing
+conversation history, and do not inspect source labels or other model outputs.
+
+Return exactly one JSON object per input record using the schema from
+`labeling-instructions-v2.md`.
+
+## Product-approved boundaries
+
+These rules override the corresponding v2 boundaries:
+
+- Exclude commands that are clearly addressed to a device, app, search engine,
+  or virtual assistant rather than another person. Examples include opening an
+  inbox, playing music, changing device volume, or showing an account value.
+  Ordinary requests sent to another person remain in scope.
+- `task`: a first-person need that implies an action is a task even when the
+  recipient is not explicit. A self-reminder is not a task. A device or virtual
+  assistant command is excluded before intent labeling.
+- `question`: an invitation phrased as a question is not a `question`.
+  Request-shaped commands are also not information questions.
+- `invitation`: an invitation phrased as a question is
+  `invitation=true`, `question=false`, and normally
+  `replyableMessage=true`.
+- `complaint`: require an explicit expression of dissatisfaction, criticism, or
+  objection. A loss, theft, malfunction, or unresolved problem without
+  expressed dissatisfaction is not a complaint.
+- `followUpReminder`: an explicit self-reminder is
+  `followUpReminder=true` and `task=false`.
+- `blessing`: require an explicit wish, prayer, congratulation, or conventional
+  blessing. Generic encouragement, happiness for someone, optimism, or “good
+  luck”-free motivational language is not sufficient. Conventional expressions
+  such as “生日快乐”, “一路顺风”, “恭喜晋升”, “happy birthday”, and
+  “congratulations on the promotion” are explicit.
+
+## Unchanged requirements
+
+- Every intent value is `true`, `false`, or `unknown`.
+- `sentiment` is `positive`, `neutral`, `negative`, or `unknown`.
+- Set `quotedOrMeta=true` for quoted, reported, searched, documented, or
+  example-only intent language.
+- Set `ambiguous=true` only when missing context materially prevents a stable
+  product label.
+- Do not output reasoning, markdown, comments, or additional fields.