feat: add worker retry and replay safety

src/core/worker/batch.py

@@ -1,5 +1,6 @@
 import time
 from dataclasses import dataclass
+from typing import Any
 
 from core.domain.models import NormalizedCDR
 
@@ -14,6 +15,7 @@ class KafkaPosition:
 @dataclass(frozen=True, slots=True)
 class BufferedCDR:
     cdr: NormalizedCDR
+    original_payload: dict[str, Any]
     position: KafkaPosition