feat: add precise validation status vocabulary for reviewer reports (Closes #406)

Introduce validation_status_vocabulary with proof-path binding for baseline-
equivalent, merge-simulation-resolved, and transient-pass labels. Wire the
assessor into final_report_validator and document the taxonomy in the
review-merge workflow.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

final_report_validator.py

@@ -20,6 +20,7 @@ from review_proofs import (
     assess_review_mutation_final_report,
     assess_validation_report,
 )
+from validation_status_vocabulary import assess_validation_status_vocabulary
 
 FINAL_REPORT_TASK_KINDS = frozenset({
     "review_pr",
@@ -598,6 +599,34 @@ def _rule_reviewer_main_checkout_baseline(report_text: str) -> list[dict[str, st
     ]
 
 
+def _rule_reviewer_validation_status_vocabulary(
+    report_text: str,
+    *,
+    action_log: list[dict] | None = None,
+) -> list[dict[str, str]]:
+    text = report_text or ""
+    if not re.search(
+        r"validation status|pr-head validation status|official validation status",
+        text,
+        re.IGNORECASE,
+    ):
+        return []
+    result = assess_validation_status_vocabulary(
+        text,
+        command_log=action_log,
+    )
+    if not result.get("block"):
+        return []
+    return _findings_from_reasons(
+        "reviewer.validation_status_vocabulary",
+        result.get("reasons") or [],
+        field="Validation status",
+        severity="block",
+        safe_next_action=result.get("safe_next_action")
+        or "use a validation status that matches the proof path executed",
+    )
+
+
 def _rule_reviewer_main_checkout_path(report_text: str) -> list[dict[str, str]]:
     text = report_text or ""
     if "baseline worktree path" not in text.lower():
@@ -902,6 +931,7 @@ _RULES_BY_TASK: dict[str, list[Callable[..., list[dict[str, str]]]]] = {
         _rule_reviewer_validation_structured,
         _rule_reviewer_linked_issue,
         _rule_reviewer_baseline_on_failure,
+        _rule_reviewer_validation_status_vocabulary,
         _rule_reviewer_main_checkout_baseline,
         _rule_reviewer_main_checkout_path,
         _rule_reviewer_already_landed_eligible,