add stream caching ("offline mode")

src/lib/types.ts

@@ -5,6 +5,7 @@ export type Track = [number, string, string];
 export interface StreamSummary {
 	id: string;
 	stream_date: number;
+	filename: string;
 	title: string | null;
 	tags: string[];
 	length_seconds: number;
@@ -12,7 +13,6 @@ export interface StreamSummary {
 
 /** The full stream shape used on the detail/player page. */
 export interface Stream extends StreamSummary {
-	filename: string;
 	format: string;
 	description: string | null;
 	tracks: Track[];