diff --git a/apps/backend/merge/progress.py b/apps/backend/merge/progress.py
index fd114337..b4d71d4c 100644
--- a/apps/backend/merge/progress.py
+++ b/apps/backend/merge/progress.py
@@ -66,7 +66,9 @@ class MergeProgressCallback(Protocol):
         percent: int,
         message: str,
         details: dict[str, Any] | None = None,
-    ) -> None: ...
+    ) -> None:
+        """no-op (abstract method)"""
+        pass
 
 
 def emit_progress(
diff --git a/apps/backend/runners/github/services/parallel_orchestrator_reviewer.py b/apps/backend/runners/github/services/parallel_orchestrator_reviewer.py
index 3910595a..d5859c58 100644
--- a/apps/backend/runners/github/services/parallel_orchestrator_reviewer.py
+++ b/apps/backend/runners/github/services/parallel_orchestrator_reviewer.py
@@ -1731,6 +1731,7 @@ For EACH finding above:
 
         # Retry loop for transient API errors
         last_error = None
+        structured_output = None
         for attempt in range(MAX_VALIDATION_RETRIES + 1):
             if attempt > 0:
                 logger.info(