fix(task): reject unknown validation status payloads

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

@@ -70,10 +70,12 @@ class ValidationResult:
         if not isinstance(payload, dict):
             return None
         raw_status = payload.get("status")
-        status: ValidationStatus | None = raw_status if raw_status in VALIDATION_STATUSES else None
+        if "status" in payload and raw_status not in VALIDATION_STATUSES:
+            raise ValueError(f"unknown validation status: {raw_status}")
+        status: ValidationStatus | None = raw_status if "status" in payload else None
         return cls(
             status=status,
-            passed=bool(payload.get("passed")) if status is None else None,
+            passed=bool(payload.get("passed")) if "status" not in payload else None,
             score=float(payload.get("score", 0.0) or 0.0),
             issues=[str(item) for item in payload.get("issues") or []],
             missing_requirements=[str(item) for item in payload.get("missing_requirements") or []],