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。

frontend/components/dashboard/ScanTerminalDashboard.tsx

@@ -672,6 +672,8 @@ function ScanTerminalScreen() {
   const userLocalTime = useUserLocalClock();
   const { themeMode } = useScanTerminalTheme();
   const [selectedRegionKey, setSelectedRegionKey] = useState<string>("east_asia");
+  const [localTimezoneOffsetSeconds, setLocalTimezoneOffsetSeconds] = useState<number | null>(null);
+  const [useLocalTimezoneDefault, setUseLocalTimezoneDefault] = useState(true);
 
   useEffect(() => {
     let cancelled = false;
@@ -743,12 +745,19 @@ function ScanTerminalScreen() {
 
   useEffect(() => {
     setSelectedRegionKey(detectLocalRegion());
+    setLocalTimezoneOffsetSeconds(-new Date().getTimezoneOffset() * 60);
+  }, []);
+
+  const selectRegionManually = useCallback((key: string) => {
+    setUseLocalTimezoneDefault(false);
+    setSelectedRegionKey(key);
   }, []);
 
   const { refreshScanTerminalManually, scanLoading, terminalData } =
     useScanTerminalQuery({
       isPro,
       proAccessLoading: !hydrated || (proAccess.loading && !canUseLocalFullAccess),
+      timezoneOffsetSeconds: useLocalTimezoneDefault ? localTimezoneOffsetSeconds : null,
       tradingRegion: selectedRegionKey,
     });
   const rows = useMemo(
@@ -831,7 +840,7 @@ function ScanTerminalScreen() {
       selectedCity={selectedCity}
       setSelectedCity={setSelectedCity}
       selectedRegionKey={selectedRegionKey}
-      setSelectedRegionKey={setSelectedRegionKey}
+      setSelectedRegionKey={selectRegionManually}
     />
   );
 }

frontend/components/dashboard/scan-terminal/scan-terminal-client.ts

@@ -53,6 +53,7 @@ type AiCityStreamEvent = {
 type TerminalQueryOptions = {
   forceRefresh?: boolean;
   signal?: AbortSignal;
+  timezoneOffsetSeconds?: number | null;
   tradingRegion?: string;
 };
 
@@ -254,6 +255,7 @@ async function readAiCityForecastStream(
 async function getTerminal({
   forceRefresh = false,
   signal,
+  timezoneOffsetSeconds,
   tradingRegion,
 }: TerminalQueryOptions = {}) {
   const params = new URLSearchParams({
@@ -271,6 +273,9 @@ async function getTerminal({
   if (tradingRegion && tradingRegion !== "all") {
     params.set("trading_region", tradingRegion);
   }
+  if (Number.isFinite(timezoneOffsetSeconds)) {
+    params.set("timezone_offset_seconds", String(Math.trunc(Number(timezoneOffsetSeconds))));
+  }
   if (forceRefresh) {
     params.set("_ts", String(Date.now()));
   }

frontend/components/dashboard/scan-terminal/use-scan-terminal-query.ts

@@ -13,10 +13,12 @@ import type { ScanTerminalResponse } from "@/lib/dashboard-types";
 export function useScanTerminalQuery({
   isPro,
   proAccessLoading,
+  timezoneOffsetSeconds,
   tradingRegion,
 }: {
   isPro: boolean;
   proAccessLoading: boolean;
+  timezoneOffsetSeconds?: number | null;
   tradingRegion?: string;
 }) {
   const {
@@ -50,12 +52,13 @@ export function useScanTerminalQuery({
           scanTerminalClient.getTerminal({
             forceRefresh,
             signal,
+            timezoneOffsetSeconds,
             tradingRegion,
           }),
         showLoading,
       });
     },
-    [isPro, proAccessLoading, run, tradingRegion],
+    [isPro, proAccessLoading, run, timezoneOffsetSeconds, tradingRegion],
   );
 
   useEffect(() => {
@@ -65,7 +68,7 @@ export function useScanTerminalQuery({
       return;
     }
     void fetchScanTerminal({ forceRefresh: false, showLoading: true });
-  }, [fetchScanTerminal, isPro, proAccessLoading, reset, tradingRegion]);
+  }, [fetchScanTerminal, isPro, proAccessLoading, reset, timezoneOffsetSeconds, tradingRegion]);
 
   const refreshScanTerminalManually = useCallback(() => {
     if (