test(task): strengthen validation status semantics

app-instance/backend/beaver/tasks/models.py

@@ -8,6 +8,7 @@ from typing import Any, Literal
 
 ValidationStatus = Literal["accepted", "rejected", "insufficient_evidence", "validator_error"]
 
+VALIDATION_STATUSES = {"accepted", "rejected", "insufficient_evidence", "validator_error"}
 TASK_OPEN_STATUSES = {"open", "running", "validating", "awaiting_feedback", "needs_review", "needs_revision"}
 
 
@@ -33,6 +34,8 @@ class ValidationResult:
         recommended_revision_prompt: str = "",
         validator: str = "heuristic",
     ) -> None:
+        if status is not None and status not in VALIDATION_STATUSES:
+            raise ValueError(f"unknown validation status: {status}")
         self.status = status or ("accepted" if passed and score >= 0.75 else "rejected")
         self.score = max(0.0, min(1.0, float(score or 0.0)))
         self.issues = list(issues or [])
@@ -67,11 +70,7 @@ class ValidationResult:
         if not isinstance(payload, dict):
             return None
         raw_status = payload.get("status")
-        status: ValidationStatus | None = (
-            raw_status
-            if raw_status in {"accepted", "rejected", "insufficient_evidence", "validator_error"}
-            else None
-        )
+        status: ValidationStatus | None = raw_status if raw_status in VALIDATION_STATUSES else None
         return cls(
             status=status,
             passed=bool(payload.get("passed")) if status is None else None,