refactor: extract _to_price_history_response helper function

Consistent with other response conversion functions in the codebase
(_to_counter_record_response, _to_invite_response, etc.)

backend/routes/audit.py

@@ -94,6 +94,17 @@ def _to_sum_record_response(record: SumRecord, email: str) -> SumRecordResponse:
     )
 
 
+def _to_price_history_response(record: PriceHistory) -> PriceHistoryResponse:
+    return PriceHistoryResponse(
+        id=record.id,
+        source=record.source,
+        pair=record.pair,
+        price=record.price,
+        timestamp=record.timestamp,
+        created_at=record.created_at,
+    )
+
+
 @router.get("/counter", response_model=PaginatedCounterRecords)
 async def get_counter_records(
     page: int = Query(1, ge=1),
@@ -173,17 +184,7 @@ async def get_price_history(
     result = await db.execute(query)
     records = result.scalars().all()
 
-    return [
-        PriceHistoryResponse(
-            id=record.id,
-            source=record.source,
-            pair=record.pair,
-            price=record.price,
-            timestamp=record.timestamp,
-            created_at=record.created_at,
-        )
-        for record in records
-    ]
+    return [_to_price_history_response(record) for record in records]
 
 
 @router.post("/price-history/fetch", response_model=PriceHistoryResponse)
@@ -216,11 +217,4 @@ async def fetch_price_now(
         result = await db.execute(query)
         record = result.scalar_one()
 
-    return PriceHistoryResponse(
-        id=record.id,
-        source=record.source,
-        pair=record.pair,
-        price=record.price,
-        timestamp=record.timestamp,
-        created_at=record.created_at,
-    )
+    return _to_price_history_response(record)