拆分 analysis_service：剩余工具函数全部移至 analysis_utils.py

提取 _mgm_hourly_high/_dedupe_forecast_daily/_format_observation_time_local/_parse_local_hour/_parse_utc_datetime/_metar_is_current_local_day/_is_plausible_city_temp。统一 parse_utc_datetime 副本。analysis_service 2082→1966 行。

web/services/scan_api.py

@@ -48,6 +48,7 @@ async def get_scan_terminal_payload(
     force_refresh: bool = False,
     region: str = "",
     skip_polymarket: bool = False,
+    timezone_offset_seconds: int | None = None,
 ) -> Dict[str, Any]:
     legacy_routes._assert_entitlement(request)
     filters: Dict[str, Any] = {
@@ -62,6 +63,8 @@ async def get_scan_terminal_payload(
         "limit": limit,
         "skip_polymarket": skip_polymarket,
     }
+    if timezone_offset_seconds is not None:
+        filters["timezone_offset_seconds"] = timezone_offset_seconds
     if region:
         filters["trading_region"] = region
     return await run_in_threadpool(