migration: preserve market insights slice

app/backend/features/themes/__init__.py

@@ -0,0 +1,3 @@
+from .service import ThemeServiceMixin
+
+__all__ = ["ThemeServiceMixin"]

app/backend/features/themes/service.py

@@ -0,0 +1,14 @@
+from __future__ import annotations
+
+from typing import Any
+
+from backend.bootstrap.config import normalize_date
+from backend.features.market.insights import MarketInsightsService
+
+
+class ThemeServiceMixin:
+    def theme_library(self, trade_date: str, force: bool = False) -> dict[str, Any]:
+        return self._market_insights().theme_library(normalize_date(trade_date), force)
+
+    def theme_detail(self, code: str, trade_date: str) -> dict[str, Any]:
+        return self._market_insights().theme_detail(code, normalize_date(trade_date))