refactor: establish standalone application boundary

app/backend/features/rotation/routes.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+from datetime import date
+from http import HTTPStatus
+from urllib.parse import parse_qs
+
+
+class RotationRoutesMixin:
+    def _handle_rotation_get(self, parsed) -> bool:
+        if parsed.path == "/api/rotation/history":
+            query = parse_qs(parsed.query)
+            trade_date = query.get("trade_date", [date.today().isoformat()])[0]
+            try:
+                self.send_json(self.application_service.rotation_history(trade_date, 9))
+            except (TypeError, ValueError) as exc:
+                self.send_json({"error": str(exc)}, HTTPStatus.BAD_REQUEST)
+            return True
+        if parsed.path == "/api/rotation/members":
+            query = parse_qs(parsed.query)
+            try:
+                self.send_json(
+                    self.application_service.rotation_sector_members(
+                        query.get("trade_date", [date.today().isoformat()])[0],
+                        query.get("sector", [""])[0],
+                    )
+                )
+            except (TypeError, ValueError) as exc:
+                self.send_json({"error": str(exc)}, HTTPStatus.BAD_REQUEST)
+            return True
+        return False