migration: preserve market insights slice

app/backend/features/popularity/service.py

@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+from typing import Any
+
+from backend.bootstrap.config import normalize_date
+from backend.features.market.insights import MarketInsightsService
+
+
+class PopularityServiceMixin:
+    def popularity(self, trade_date: str, force: bool = False) -> dict[str, Any]:
+        return self._market_insights().popularity(normalize_date(trade_date), force)