refactor: establish standalone application boundary

app/backend/features/system/routes.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+from datetime import datetime
+from http import HTTPStatus
+
+
+class SystemRoutesMixin:
+    def _handle_system_public_get(self, parsed) -> bool:
+        if parsed.path == "/api/health":
+            self.send_json(
+                {
+                    "ok": True,
+                    "storage": "sqlite",
+                    "account_required": True,
+                    "time": datetime.now().astimezone().isoformat(timespec="seconds"),
+                }
+            )
+            return True
+        return False
+
+    def _handle_system_get(self, parsed) -> bool:
+        if parsed.path == "/api/admin/settings":
+            self.send_json(
+                {"ok": True, **self.application_service.system_status(), "users": self.application_service.admin_users()}
+            )
+            return True
+        return False
+
+    def backfill_data(self) -> None:
+        try:
+            body = self.read_json_body()
+            results = self.application_service.backfill(
+                str(body.get("start_date") or ""),
+                str(body.get("end_date") or ""),
+            )
+            self.send_json({"ok": True, "results": results})
+        except ValueError as exc:
+            self.send_json({"error": str(exc)}, HTTPStatus.BAD_REQUEST)
+        except Exception as exc:
+            self.send_json({"error": f"历史回补失败：{exc}"}, HTTPStatus.INTERNAL_SERVER_ERROR)