Coerce bare-int quantity/price to Decimal in enrich_parsed

GPT-4.1 cross-family review of the final PR diff (no BLOCK) flagged
residual type drift: parse_float=Decimal rules out floats on the LLM
path, but a bare JSON int survived as Python int. Coerce it so both
parse paths emit one canonical Decimal type.

lambdas/po/email_processor/handler.py

@@ -373,6 +373,11 @@ def enrich_parsed(parsed: dict, s3_key: str, email_subject: str):
                     item[field] = Decimal(value.replace(",", "").strip())
                 except InvalidOperation:
                     pass
+            elif isinstance(value, (int, float)) and not isinstance(value, bool):
+                # parse_float=Decimal means floats can't occur on the LLM path,
+                # but a bare JSON int would slip through as Python int; coerce
+                # so both paths emit one canonical Decimal type (cross-review FIX).
+                item[field] = Decimal(str(value))
     return parsed