/**
 * Returns the **live start time** in milliseconds since the Unix epoch.
 *
 * This hook provides a reactive way to observe and respond to changes in the live stream’s
 * **start time**, as reported by the manifest. This is typically used to calculate
 * absolute playback positions or to display timestamps in live and DVR playback UIs.
 *
 * A live HLS stream must include the `EXT-X-PROGRAM-DATE-TIME` tag for this value
 * to be available.
 *
 * ### Platform behavior
 * - **HLS:** Supported on both Android and iOS.
 * - **DASH:** Not available on iOS (value will always be `null`).
 *
 * ⚠️ Must be used within a {@link PlayerProvider} or
 * [AVPlayerViewControllerProvider](../../ios-avplayerviewcontroller-plugin-api/variables/AVPlayerViewControllerProvider.md) component.
 *
 * @returns `{number | null}` The live start time in **milliseconds since the epoch**, or `null`
 * if unavailable or not applicable (e.g., VOD playback).
 *
 * @example
 * ```tsx
 * import React from 'react';
 * import { View, Text } from 'react-native';
 * import {
 *   useLive,
 *   useLiveStartTime,
 *   usePosition,
 * } from '@castlabs/react-native-prestoplay';
 *
 * export default function LiveTimeDisplay() {
 *   const isLive = useLive();
 *   const liveStartTime = useLiveStartTime();
 *   const position = usePosition();
 *
 *   if (!isLive || !liveStartTime) {
 *     return <Text>Not a live stream</Text>;
 *   }
 *
 *   const wallClockTime = new Date(liveStartTime + position).toLocaleTimeString();
 *
 *   return (
 *     <View>
 *       <Text>Live start: {new Date(liveStartTime).toLocaleTimeString()}</Text>
 *       <Text>Current time: {wallClockTime}</Text>
 *     </View>
 *   );
 * }
 * ```
 *
 * @group Hooks
 */
export default function useLiveStartTime(): number | null;