colocate typings

src/lib/audio/episode-details.ts

@@ -1,5 +1,5 @@
+import type { EpisodeDetails } from '$lib/types';
 import { writable } from 'svelte/store';
 
-export type EpisodeDetails = Record<string, string | number | boolean> | null;
-export const episode_details = writable<EpisodeDetails>(null);
+export const episode_details = writable<EpisodeDetails | null>(null);
 export type EpisodeDetailsStore = typeof episode_details;