fix: tolerate spotify version suffixes and surface rerank failures

backend/app/pipeline/grounding.py

@@ -274,6 +274,13 @@ class Grounder:
         status = (
             ResolutionStatus.MISMATCH if field_results or bare_results else ResolutionStatus.MISS
         )
+        structlog.get_logger().info(
+            "candidate_unresolved",
+            title=candidate.title,
+            artist=candidate.artist,
+            status=status,
+            result_count=len(field_results) + len(bare_results),
+        )
         return _ResolutionAttempt(index=index, status=status)