Fix browser time format handling (#22694)

* implement hook to return resolved "24hour" | "12hour" string

delegate to existing use24HourTime(), which correctly detects the browser's locale preference via Intl.DateTimeFormat

* update frontend to use use24HourTime(config) or useTimeFormat(config) instead of directly comparing config.ui.time_format

web/src/hooks/use-draggable-element.ts

@@ -4,6 +4,7 @@ import { FrigateConfig } from "@/types/frigateConfig";
 import useSWR from "swr";
 import { formatUnixTimestampToDateTime } from "@/utils/dateUtil";
 import { useDateLocale } from "./use-date-locale";
+import { useTimeFormat } from "./use-date-utils";
 import { useTranslation } from "react-i18next";
 import useUserInteraction from "./use-user-interaction";
 
@@ -168,7 +169,7 @@ function useDraggableElement({
   const { t } = useTranslation(["common"]);
   const locale = useDateLocale();
 
-  const timeFormat = config?.ui.time_format === "24hour" ? "24hour" : "12hour";
+  const timeFormat = useTimeFormat(config);
   const format = useMemo(() => {
     const formatKey = `time.${
       segmentDuration < 60 && !dense