fix(sp41): drop unused write_pipeline_a_files test import + clarify RebillClaim docstring

backend/src/cyclone/rebill/pipeline_a.py

@@ -19,7 +19,9 @@ from cyclone.rebill.reconcile import ReconcileOutcome, OutcomeCategory
 
 @dataclass(frozen=True)
 class RebillClaim:
-    """Pre-emission 837P shape for Pipeline A. The serializer adapter (Task 12) converts this to a ClaimOutput for serialize_837."""
+    """Pre-emission 837P shape for Pipeline A. The orchestrator's serializer
+    adapter converts this to a ClaimOutput for serialize_837.
+    """
 
     claim_id: str           # reuses original claim_submit_id
     member_id: str

backend/tests/test_rebill_pipeline_a.py

@@ -1,10 +1,7 @@
 """Pipeline A: denied/partial visits become frequency-7 replacement claims."""
 from datetime import date
 from decimal import Decimal
-from cyclone.rebill.pipeline_a import (
-    build_pipeline_a_claims,
-    write_pipeline_a_files,
-)
+from cyclone.rebill.pipeline_a import build_pipeline_a_claims
 from cyclone.rebill.reconcile import VisitRow, ReconcileOutcome, OutcomeCategory
 from cyclone.rebill.carc_filter import CarcDecision