feat: require validation cwd and HEAD proof in reviewer reports (Closes #398)

Rebased onto current prgs/master; merged with #396 validation failure
history by keeping both validator rules and workflow handoff fields.

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

final_report_validator.py

@@ -490,6 +490,42 @@ def _rule_reviewer_validation_failure_history(
     ]
 
 
+def _rule_reviewer_validation_cwd_proof(
+    report_text: str,
+    *,
+    validation_session: dict | None = None,
+) -> list[dict[str, str]]:
+    from reviewer_validation_cwd_proof import assess_validation_cwd_proof_report
+
+    session = validation_session or {}
+    claims = (
+        session.get("validation_ran")
+        or session.get("command")
+        or session.get("baseline_validation_ran")
+    )
+    if not claims and "validation command:" not in (report_text or "").lower():
+        return []
+
+    result = assess_validation_cwd_proof_report(
+        report_text,
+        validation_session=session,
+    )
+    if result.get("proven") or not result.get("claims_validation"):
+        return []
+    severity = "block" if result.get("violations") else "downgrade"
+    return [
+        validator_finding(
+            "reviewer.validation_cwd_proof",
+            severity,
+            "Validation cwd/HEAD proof",
+            reason,
+            result.get("safe_next_action")
+            or "document pwd, HEAD SHA, and explicit cwd before validation",
+        )
+        for reason in (result.get("violations") or result.get("reasons") or ["incomplete"])
+    ]
+
+
 def _rule_reviewer_validation_command(report_text: str) -> list[dict[str, str]]:
     text = report_text or ""
     if not _BARE_PYTEST_RE.search(text):
@@ -899,6 +935,7 @@ _RULES_BY_TASK: dict[str, list[Callable[..., list[dict[str, str]]]]] = {
         _rule_reviewer_git_fetch_readonly,
         _rule_reviewer_validation_command,
         _rule_reviewer_validation_failure_history,
+        _rule_reviewer_validation_cwd_proof,
         _rule_reviewer_validation_structured,
         _rule_reviewer_linked_issue,
         _rule_reviewer_baseline_on_failure,