refactor: establish standalone application boundary

app/backend/features/sentiment/routes.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+from datetime import date
+from http import HTTPStatus
+from urllib.parse import parse_qs
+
+
+class SentimentRoutesMixin:
+    def _handle_sentiment_get(self, parsed) -> bool:
+        if parsed.path == "/api/sentiment/history":
+            query = parse_qs(parsed.query)
+            trade_date = query.get("trade_date", [date.today().isoformat()])[0]
+            try:
+                limit = int(query.get("limit", ["20"])[0])
+                self.send_json(self.application_service.sentiment_history(trade_date, limit))
+            except (TypeError, ValueError) as exc:
+                self.send_json({"error": str(exc)}, HTTPStatus.BAD_REQUEST)
+            return True
+        return False